How to conert local time to UTC time in android [duplicate]

How to conert local time to UTC time in android [duplicate] - android

Want to improve this post? Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted.
When I create a new Date object, it is initialized to the current time but in the local timezone. How can I get the current date and time in GMT?

tl;dr
Instant.now() // Capture the current moment in UTC.
Generate a String to represent that value:
Instant.now().toString()
2016-09-13T23:30:52.123Z
Details
As the correct answer by Jon Skeet stated, a java.util.Date object has no time zone†. But its toString implementation applies the JVM’s default time zone when generating the String representation of that date-time value. Confusingly to the naïve programmer, a Date seems to have a time zone but does not.
The java.util.Date, j.u.Calendar, and java.text.SimpleDateFormat classes bundled with Java are notoriously troublesome. Avoid them. Instead, use either of these competent date-time libraries:
java.time.* package in Java 8
Joda-Time
java.time (Java 8)
Java 8 brings an excellent new java.time.* package to supplant the old java.util.Date/Calendar classes.
Getting current time in UTC/GMT is a simple one-liner…
Instant instant = Instant.now();
That Instant class is the basic building block in java.time, representing a moment on the timeline in UTC with a resolution of nanoseconds.
In Java 8, the current moment is captured with only up to milliseconds resolution. Java 9 brings a fresh implementation of Clock captures the current moment in up to the full nanosecond capability of this class, depending on the ability of your host computer’s clock hardware.
It’s toString method generates a String representation of its value using one specific ISO 8601 format. That format outputs zero, three, six or nine digits digits (milliseconds, microseconds, or nanoseconds) as necessary to represent the fraction-of-second.
If you want more flexible formatting, or other additional features, then apply an offset-from-UTC of zero, for UTC itself (ZoneOffset.UTC constant) to get a OffsetDateTime.
OffsetDateTime now = OffsetDateTime.now( ZoneOffset.UTC );
Dump to console…
System.out.println( "now.toString(): " + now );
When run…
now.toString(): 2014-01-21T23:42:03.522Z
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android bundle implementations of the java.time classes.
For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.
Joda-Time
UPDATE: The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
Using the Joda-Time 3rd-party open-source free-of-cost library, you can get the current date-time in just one line of code.
Joda-Time inspired the new java.time.* classes in Java 8, but has a different architecture. You may use Joda-Time in older versions of Java. Joda-Time continues to work in Java 8 and continues to be actively maintained (as of 2014). However, the Joda-Time team does advise migration to java.time.
System.out.println( "UTC/GMT date-time in ISO 8601 format: " + new org.joda.time.DateTime( org.joda.time.DateTimeZone.UTC ) );
More detailed example code (Joda-Time 2.3)…
org.joda.time.DateTime now = new org.joda.time.DateTime(); // Default time zone.
org.joda.time.DateTime zulu = now.toDateTime( org.joda.time.DateTimeZone.UTC );
Dump to console…
System.out.println( "Local time in ISO 8601 format: " + now );
System.out.println( "Same moment in UTC (Zulu): " + zulu );
When run…
Local time in ISO 8601 format: 2014-01-21T15:34:29.933-08:00
Same moment in UTC (Zulu): 2014-01-21T23:34:29.933Z
For more example code doing time zone work, see my answer to a similar question.
Time Zone
I recommend you always specify a time zone rather than relying implicitly on the JVM’s current default time zone (which can change at any moment!). Such reliance seems to be a common cause of confusion and bugs in date-time work.
When calling now() pass the desired/expected time zone to be assigned. Use the DateTimeZone class.
DateTimeZone zoneMontréal = DateTimeZone.forID( "America/Montreal" );
DateTime now = DateTime.now( zoneMontréal );
That class holds a constant for UTC time zone.
DateTime now = DateTime.now( DateTimeZone.UTC );
If you truly want to use the JVM’s current default time zone, make an explicit call so your code is self-documenting.
DateTimeZone zoneDefault = DateTimeZone.getDefault();
ISO 8601
Read about ISO 8601 formats. Both java.time and Joda-Time use that standard’s sensible formats as their defaults for both parsing and generating strings.
† Actually, java.util.Date does have a time zone, buried deep under layers of source code. For most practical purposes, that time zone is ignored. So, as shorthand, we say java.util.Date has no time zone. Furthermore, that buried time zone is not the one used by Date’s toString method; that method uses the JVM’s current default time zone. All the more reason to avoid this confusing class and stick with Joda-Time and java.time.

java.util.Date has no specific time zone, although its value is most commonly thought of in relation to UTC. What makes you think it's in local time?
To be precise: the value within a java.util.Date is the number of milliseconds since the Unix epoch, which occurred at midnight January 1st 1970, UTC. The same epoch could also be described in other time zones, but the traditional description is in terms of UTC. As it's a number of milliseconds since a fixed epoch, the value within java.util.Date is the same around the world at any particular instant, regardless of local time zone.
I suspect the problem is that you're displaying it via an instance of Calendar which uses the local timezone, or possibly using Date.toString() which also uses the local timezone, or a SimpleDateFormat instance, which, by default, also uses local timezone.
If this isn't the problem, please post some sample code.
I would, however, recommend that you use Joda-Time anyway, which offers a much clearer API.

SimpleDateFormat dateFormatGmt = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
dateFormatGmt.setTimeZone(TimeZone.getTimeZone("GMT"));
//Local time zone
SimpleDateFormat dateFormatLocal = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
//Time in GMT
return dateFormatLocal.parse( dateFormatGmt.format(new Date()) );

This definitely returns UTC time: as String and Date objects !
static final String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";
public static Date getUTCdatetimeAsDate() {
// note: doesn't check for null
return stringDateToDate(getUTCdatetimeAsString());
}
public static String getUTCdatetimeAsString() {
final SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
final String utcTime = sdf.format(new Date());
return utcTime;
}
public static Date stringDateToDate(String StrDate) {
Date dateToReturn = null;
SimpleDateFormat dateFormat = new SimpleDateFormat(DATEFORMAT);
try {
dateToReturn = (Date)dateFormat.parse(StrDate);
}
catch (ParseException e) {
e.printStackTrace();
}
return dateToReturn;
}

Calendar c = Calendar.getInstance();
System.out.println("current: "+c.getTime());
TimeZone z = c.getTimeZone();
int offset = z.getRawOffset();
if(z.inDaylightTime(new Date())){
offset = offset + z.getDSTSavings();
}
int offsetHrs = offset / 1000 / 60 / 60;
int offsetMins = offset / 1000 / 60 % 60;
System.out.println("offset: " + offsetHrs);
System.out.println("offset: " + offsetMins);
c.add(Calendar.HOUR_OF_DAY, (-offsetHrs));
c.add(Calendar.MINUTE, (-offsetMins));
System.out.println("GMT Time: "+c.getTime());

Actually not time, but it's representation could be changed.
SimpleDateFormat f = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
f.setTimeZone(TimeZone.getTimeZone("UTC"));
System.out.println(f.format(new Date()));
Time is the same in any point of the Earth, but our perception of time could be different depending on location.

This works for getting UTC milliseconds in Android.
Calendar c = Calendar.getInstance();
int utcOffset = c.get(Calendar.ZONE_OFFSET) + c.get(Calendar.DST_OFFSET);
Long utcMilliseconds = c.getTimeInMillis() + utcOffset;

Calendar aGMTCalendar = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
Then all operations performed using the aGMTCalendar object will be done with the GMT time zone and will not have the daylight savings time or fixed offsets applied
Wrong!
Calendar aGMTCalendar = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
aGMTCalendar.getTime(); //or getTimeInMillis()
and
Calendar aNotGMTCalendar = Calendar.getInstance(TimeZone.getTimeZone("GMT-2"));aNotGMTCalendar.getTime();
will return the same time. Idem for
new Date(); //it's not GMT.

This code prints the current time UTC.
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
public class Test
{
public static void main(final String[] args) throws ParseException
{
final SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss z");
f.setTimeZone(TimeZone.getTimeZone("UTC"));
System.out.println(f.format(new Date()));
}
}
Result
2013-10-26 14:37:48 UTC

Here is what seems to be incorrect in Jon Skeet's answer. He said:
java.util.Date is always in UTC. What makes you think it's in local
time? I suspect the problem is that you're displaying it via an
instance of Calendar which uses the local timezone, or possibly using
Date.toString() which also uses the local timezone.
However, the code:
System.out.println(new java.util.Date().getHours() + " hours");
gives the local hours, not GMT (UTC hours), using no Calendar and no SimpleDateFormat at all.
That is why is seems something is incorrect.
Putting together the responses, the code:
System.out.println(Calendar.getInstance(TimeZone.getTimeZone("GMT"))
.get(Calendar.HOUR_OF_DAY) + " Hours");
shows the GMT hours instead of the local hours -- note that getTime.getHours() is missing because that would create a Date() object, which theoretically stores the date in GMT, but gives back the hours in the local time zone.

If you want a Date object with fields adjusted for UTC you can do it like this with Joda Time:
import org.joda.time.DateTimeZone;
import java.util.Date;
...
Date local = new Date();
System.out.println("Local: " + local);
DateTimeZone zone = DateTimeZone.getDefault();
long utc = zone.convertLocalToUTC(local.getTime(), false);
System.out.println("UTC: " + new Date(utc));

You can use:
Calendar aGMTCalendar = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
Then all operations performed using the aGMTCalendar object will be done with the GMT time zone and will not have the daylight savings time or fixed offsets applied. I think the previous poster is correct that the Date() object always returns a GMT it's not until you go to do something with the date object that it gets converted to the local time zone.

SimpleDateFormat dateFormatGmt = new SimpleDateFormat("yyyy-MM-dd");
dateFormatGmt.setTimeZone(TimeZone.getTimeZone("GMT"));
System.out.println(dateFormatGmt.format(date));

Here is my implementation of toUTC:
public static Date toUTC(Date date){
long datems = date.getTime();
long timezoneoffset = TimeZone.getDefault().getOffset(datems);
datems -= timezoneoffset;
return new Date(datems);
}
There's probably several ways to improve it, but it works for me.

You can directly use this
SimpleDateFormat dateFormatGmt = new SimpleDateFormat("dd:MM:yyyy HH:mm:ss");
dateFormatGmt.setTimeZone(TimeZone.getTimeZone("GMT"));
System.out.println(dateFormatGmt.format(new Date())+"");

Here an other suggestion to get a GMT Timestamp object:
import java.sql.Timestamp;
import java.util.Calendar;
...
private static Timestamp getGMT() {
Calendar cal = Calendar.getInstance();
return new Timestamp(cal.getTimeInMillis()
-cal.get(Calendar.ZONE_OFFSET)
-cal.get(Calendar.DST_OFFSET));
}

Here is another way to get GMT time in String format
String DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss z" ;
final SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
String dateTimeString = sdf.format(new Date());

With:
Calendar cal = Calendar.getInstance();
Then cal have the current date and time.
You also could get the current Date and Time for timezone with:
Calendar cal2 = Calendar.getInstance(TimeZone.getTimeZone("GMT-2"));
You could ask cal.get(Calendar.DATE); or other Calendar constant about others details.
Date and Timestamp are deprecated in Java. Calendar class it isn't.

Sample code to render system time in a specific time zone and a specific format.
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;
public class TimZoneTest {
public static void main (String[] args){
//<GMT><+/-><hour>:<minutes>
// Any screw up in this format, timezone defaults to GMT QUIETLY. So test your format a few times.
System.out.println(my_time_in("GMT-5:00", "MM/dd/yyyy HH:mm:ss") );
System.out.println(my_time_in("GMT+5:30", "'at' HH:mm a z 'on' MM/dd/yyyy"));
System.out.println("---------------------------------------------");
// Alternate format
System.out.println(my_time_in("America/Los_Angeles", "'at' HH:mm a z 'on' MM/dd/yyyy") );
System.out.println(my_time_in("America/Buenos_Aires", "'at' HH:mm a z 'on' MM/dd/yyyy") );
}
public static String my_time_in(String target_time_zone, String format){
TimeZone tz = TimeZone.getTimeZone(target_time_zone);
Date date = Calendar.getInstance().getTime();
SimpleDateFormat date_format_gmt = new SimpleDateFormat(format);
date_format_gmt.setTimeZone(tz);
return date_format_gmt.format(date);
}
}
Output
10/08/2011 21:07:21
at 07:37 AM GMT+05:30 on 10/09/2011
at 19:07 PM PDT on 10/08/2011
at 23:07 PM ART on 10/08/2011

Just to make this simpler, to create a Date in UTC you can use Calendar :
Calendar.getInstance(TimeZone.getTimeZone("UTC"));
Which will construct a new instance for Calendar using the "UTC" TimeZone.
If you need a Date object from that calendar you could just use getTime().

Converting Current DateTime in UTC:
DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
DateTimeZone dateTimeZone = DateTimeZone.getDefault(); //Default Time Zone
DateTime currDateTime = new DateTime(); //Current DateTime
long utcTime = dateTimeZone.convertLocalToUTC(currDateTime .getMillis(), false);
String currTime = formatter.print(utcTime); //UTC time converted to string from long in format of formatter
currDateTime = formatter.parseDateTime(currTime); //Converted to DateTime in UTC

public static void main(String args[]){
LocalDate date=LocalDate.now();
System.out.println("Current date = "+date);
}

This worked for me, returns the timestamp in GMT!
Date currDate;
SimpleDateFormat dateFormatGmt = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
dateFormatGmt.setTimeZone(TimeZone.getTimeZone("GMT"));
SimpleDateFormat dateFormatLocal = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
long currTime = 0;
try {
currDate = dateFormatLocal.parse( dateFormatGmt.format(new Date()) );
currTime = currDate.getTime();
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

The Simple Function that you can use:
Edit: this version uses the modern java.time classes.
private static final DateTimeFormatter FORMATTER
= DateTimeFormatter.ofPattern("dd-MM-uuuu HH:mm:ss z");
public static String getUtcDateTime() {
return ZonedDateTime.now(ZoneId.of("Etc/UTC")).format(FORMATTER);
}
Return value from the method:
26-03-2022 17:38:55 UTC
Original function:
public String getUTC_DateTime() {
SimpleDateFormat dateTimeFormat = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss z");
dateTimeFormat.setTimeZone(TimeZone.getTimeZone("UTC"));//gmt
return dateTimeFormat.format(new Date());
}
return of above function:
26-03-2022 08:07:21 UTC

To put it simple. A calendar object stores information about time zone but when you perform cal.getTime() then the timezone information will be lost. So for Timezone conversions I will advice to use DateFormat classes...

this is my implementation:
public static String GetCurrentTimeStamp()
{
Calendar cal=Calendar.getInstance();
long offset = cal.getTimeZone().getOffset(System.currentTimeMillis());//if you want in UTC else remove it .
return new java.sql.Timestamp(System.currentTimeMillis()+offset).toString();
}

Use this Class to get ever the right UTC Time from a Online NTP Server:
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
class NTP_UTC_Time
{
private static final String TAG = "SntpClient";
private static final int RECEIVE_TIME_OFFSET = 32;
private static final int TRANSMIT_TIME_OFFSET = 40;
private static final int NTP_PACKET_SIZE = 48;
private static final int NTP_PORT = 123;
private static final int NTP_MODE_CLIENT = 3;
private static final int NTP_VERSION = 3;
// Number of seconds between Jan 1, 1900 and Jan 1, 1970
// 70 years plus 17 leap days
private static final long OFFSET_1900_TO_1970 = ((365L * 70L) + 17L) * 24L * 60L * 60L;
private long mNtpTime;
public boolean requestTime(String host, int timeout) {
try {
DatagramSocket socket = new DatagramSocket();
socket.setSoTimeout(timeout);
InetAddress address = InetAddress.getByName(host);
byte[] buffer = new byte[NTP_PACKET_SIZE];
DatagramPacket request = new DatagramPacket(buffer, buffer.length, address, NTP_PORT);
buffer[0] = NTP_MODE_CLIENT | (NTP_VERSION << 3);
writeTimeStamp(buffer, TRANSMIT_TIME_OFFSET);
socket.send(request);
// read the response
DatagramPacket response = new DatagramPacket(buffer, buffer.length);
socket.receive(response);
socket.close();
mNtpTime = readTimeStamp(buffer, RECEIVE_TIME_OFFSET);
} catch (Exception e) {
// if (Config.LOGD) Log.d(TAG, "request time failed: " + e);
return false;
}
return true;
}
public long getNtpTime() {
return mNtpTime;
}
/**
* Reads an unsigned 32 bit big endian number from the given offset in the buffer.
*/
private long read32(byte[] buffer, int offset) {
byte b0 = buffer[offset];
byte b1 = buffer[offset+1];
byte b2 = buffer[offset+2];
byte b3 = buffer[offset+3];
// convert signed bytes to unsigned values
int i0 = ((b0 & 0x80) == 0x80 ? (b0 & 0x7F) + 0x80 : b0);
int i1 = ((b1 & 0x80) == 0x80 ? (b1 & 0x7F) + 0x80 : b1);
int i2 = ((b2 & 0x80) == 0x80 ? (b2 & 0x7F) + 0x80 : b2);
int i3 = ((b3 & 0x80) == 0x80 ? (b3 & 0x7F) + 0x80 : b3);
return ((long)i0 << 24) + ((long)i1 << 16) + ((long)i2 << 8) + (long)i3;
}
/**
* Reads the NTP time stamp at the given offset in the buffer and returns
* it as a system time (milliseconds since January 1, 1970).
*/
private long readTimeStamp(byte[] buffer, int offset) {
long seconds = read32(buffer, offset);
long fraction = read32(buffer, offset + 4);
return ((seconds - OFFSET_1900_TO_1970) * 1000) + ((fraction * 1000L) / 0x100000000L);
}
/**
* Writes 0 as NTP starttime stamp in the buffer. --> Then NTP returns Time OFFSET since 1900
*/
private void writeTimeStamp(byte[] buffer, int offset) {
int ofs = offset++;
for (int i=ofs;i<(ofs+8);i++)
buffer[i] = (byte)(0);
}
}
And use it with:
long now = 0;
NTP_UTC_Time client = new NTP_UTC_Time();
if (client.requestTime("pool.ntp.org", 2000)) {
now = client.getNtpTime();
}
If you need UTC Time "now" as DateTimeString use function:
private String get_UTC_Datetime_from_timestamp(long timeStamp){
try{
Calendar cal = Calendar.getInstance();
TimeZone tz = cal.getTimeZone();
int tzt = tz.getOffset(System.currentTimeMillis());
timeStamp -= tzt;
// DateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss",Locale.getDefault());
DateFormat sdf = new SimpleDateFormat();
Date netDate = (new Date(timeStamp));
return sdf.format(netDate);
}
catch(Exception ex){
return "";
}
}
and use it with:
String UTC_DateTime = get_UTC_Datetime_from_timestamp(now);

If you want to avoid parsing the date and just want a timestamp in GMT, you could use:
final Date gmt = new Timestamp(System.currentTimeMillis()
- Calendar.getInstance().getTimeZone()
.getOffset(System.currentTimeMillis()));

public class CurrentUtcDate
{
public static void main(String[] args) {
Date date = new Date();
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
System.out.println("UTC Time is: " + dateFormat.format(date));
}
}
Output:
UTC Time is: 22-01-2018 13:14:35
You can change the date format as needed.

Current date in the UTC
Instant.now().toString().replaceAll("T.*", "");

Related

Check to see if current time is 00:00:00 [duplicate]

How can I get the current time and date in an Android app?

You could use:
import java.util.Calendar;
import java.util.Date;
Date currentTime = Calendar.getInstance().getTime();
There are plenty of constants in Calendar for everything you need.
Check the Calendar class documentation.

You can (but no longer should - see below!) use android.text.format.Time:
Time now = new Time();
now.setToNow();
From the reference linked above:
The Time class is a faster replacement
for the java.util.Calendar and
java.util.GregorianCalendar classes.
An instance of the Time class
represents a moment in time, specified
with second precision.
NOTE 1:
It's been several years since I wrote this answer,
and it is about an old, Android-specific and now deprecated class.
Google now says that
"[t]his class has a number of issues and it is recommended that GregorianCalendar is used instead".
NOTE 2: Even though the Time class has a toMillis(ignoreDaylightSavings) method, this is merely a convenience to pass to methods that expect time in milliseconds. The time value is only precise to one second; the milliseconds portion is always 000. If in a loop you do
Time time = new Time(); time.setToNow();
Log.d("TIME TEST", Long.toString(time.toMillis(false)));
... do something that takes more than one millisecond, but less than one second ...
The resulting sequence will repeat the same value, such as 1410543204000, until the next second has started, at which time 1410543205000 will begin to repeat.

If you want to get the date and time in a specific pattern you can use the following:
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd_HHmmss", Locale.getDefault());
String currentDateandTime = sdf.format(new Date());
Or,
Date:
String currentDate = new SimpleDateFormat("dd-MM-yyyy", Locale.getDefault()).format(new Date());
Time:
String currentTime = new SimpleDateFormat("HH:mm:ss", Locale.getDefault()).format(new Date());

For those who might rather prefer a customized format, you can use:
DateFormat df = new SimpleDateFormat("EEE, d MMM yyyy, HH:mm");
String date = df.format(Calendar.getInstance().getTime());
Whereas you can have DateFormat patterns such as:
"yyyy.MM.dd G 'at' HH:mm:ss z" ---- 2001.07.04 AD at 12:08:56 PDT
"hh 'o''clock' a, zzzz" ----------- 12 o'clock PM, Pacific Daylight Time
"EEE, d MMM yyyy HH:mm:ss Z"------- Wed, 4 Jul 2001 12:08:56 -0700
"yyyy-MM-dd'T'HH:mm:ss.SSSZ"------- 2001-07-04T12:08:56.235-0700
"yyMMddHHmmssZ"-------------------- 010704120856-0700
"K:mm a, z" ----------------------- 0:08 PM, PDT
"h:mm a" -------------------------- 12:08 PM
"EEE, MMM d, ''yy" ---------------- Wed, Jul 4, '01

Actually, it's safer to set the current timezone set on the device with Time.getCurrentTimezone(), or else you will get the current time in UTC.
Time today = new Time(Time.getCurrentTimezone());
today.setToNow();
Then, you can get all the date fields you want, like, for example:
textViewDay.setText(today.monthDay + ""); // Day of the month (1-31)
textViewMonth.setText(today.month + ""); // Month (0-11)
textViewYear.setText(today.year + ""); // Year
textViewTime.setText(today.format("%k:%M:%S")); // Current time
See android.text.format.Time class for all the details.
UPDATE
As many people are pointing out, Google says this class has a number of issues and is not supposed to be used anymore:
This class has a number of issues and it is recommended that
GregorianCalendar is used instead.
Known issues:
For historical reasons when performing time calculations all
arithmetic currently takes place using 32-bit integers. This limits
the reliable time range representable from 1902 until 2037.See the
wikipedia article on the Year 2038 problem for details. Do not rely on
this behavior; it may change in the future. Calling
switchTimezone(String) on a date that cannot exist, such as a wall
time that was skipped due to a DST transition, will result in a date
in 1969 (i.e. -1, or 1 second before 1st Jan 1970 UTC). Much of the
formatting / parsing assumes ASCII text and is therefore not suitable
for use with non-ASCII scripts.

tl;dr
Instant.now() // Current moment in UTC.
…or…
ZonedDateTime.now( ZoneId.of( "America/Montreal" ) ) // In a particular time zone
Details
The other answers, while correct, are outdated. The old date-time classes have proven to be poorly designed, confusing, and troublesome.
java.time
Those old classes have been supplanted by the java.time framework.
Java 8 and later: The java.time framework is built-in.
Java 7 & 6: Use the backport of java.time.
Android: Use this wrapped version of that backport.
These new classes are inspired by the highly successful Joda-Time project, defined by JSR 310, and extended by the ThreeTen-Extra project.
See the Oracle Tutorial.
Instant
An Instant is a moment on the timeline in UTC with resolution up to nanoseconds.
Instant instant = Instant.now(); // Current moment in UTC.
Time Zone
Apply a time zone (ZoneId) to get a ZonedDateTime. If you omit the time zone your JVM’s current default time zone is implicitly applied. Better to specify explicitly the desired/expected time zone.
Use proper time zone names in the format of continent/region such as America/Montreal, Europe/Brussels, or Asia/Kolkata. Never use the 3-4 letter abbreviations such as EST or IST as they are neither standardized nor unique.
ZoneId zoneId = ZoneId.of( "America/Montreal" ); // Or "Asia/Kolkata", "Europe/Paris", and so on.
ZonedDateTime zdt = ZonedDateTime.ofInstant( instant , zoneId );
Generating Strings
You can easily generate a String as a textual representation of the date-time value. You can go with a standard format, your own custom format, or an automatically localized format.
ISO 8601
You can call the toString methods to get text formatted using the common and sensible ISO 8601 standard.
String output = instant.toString();
2016-03-23T03:09:01.613Z
Note that for ZonedDateTime, the toString method extends the ISO 8601 standard by appending the name of the time zone in square brackets. Extremely useful and important information, but not standard.
2016-03-22T20:09:01.613-08:00[America/Los_Angeles]
Custom format
Or specify your own particular formatting pattern with the DateTimeFormatter class.
DateTimeFormatter formatter = DateTimeFormatter.ofPattern( "dd/MM/yyyy hh:mm a" );
Specify a Locale for a human language (English, French, etc.) to use in translating the name of day/month and also in defining cultural norms such as the order of year and month and date. Note that Locale has nothing to do with time zone.
formatter = formatter.withLocale( Locale.US ); // Or Locale.CANADA_FRENCH or such.
String output = zdt.format( formatter );
Localizing
Better yet, let java.time do the work of localizing automatically.
DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDateTime( FormatStyle.MEDIUM );
String output = zdt.format( formatter.withLocale( Locale.US ) ); // Or Locale.CANADA_FRENCH and so on.
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes. Hibernate 5 & JPA 2.2 support java.time.
Where can the java.time classes be obtained?
Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
Java 9 brought some minor features and fixes.
Java SE 6 and Java SE 7
Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android (26+) bundle implementations of the java.time classes.
For earlier Android (<26), the process of API desugaring brings a subset of the java.time functionality not originally built into Android.
If the desugaring does not offer what you need, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above) to Android. See How to use ThreeTenABP….

For the current date and time, use:
String mydate = java.text.DateFormat.getDateTimeInstance().format(Calendar.getInstance().getTime());
Which outputs:
Feb 27, 2012 5:41:23 PM

Try with the following way. All formats are given below to get the date and time formats.
Calendar c = Calendar.getInstance();
SimpleDateFormat dateformat = new SimpleDateFormat("dd-MMM-yyyy hh:mm:ss aa");
String datetime = dateformat.format(c.getTime());
System.out.println(datetime);

To ge the current time you can use System.currentTimeMillis() which is standard in Java. Then you can use it to create a date
Date currentDate = new Date(System.currentTimeMillis());
And as mentioned by others to create a time
Time currentTime = new Time();
currentTime.setToNow();

You can use the code:
Calendar c = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String strDate = sdf.format(c.getTime());
Output:
2014-11-11 00:47:55
You also get some more formatting options for SimpleDateFormat from here.

Easy. You can dissect the time to get separate values for current time, as follows:
Calendar cal = Calendar.getInstance();
int millisecond = cal.get(Calendar.MILLISECOND);
int second = cal.get(Calendar.SECOND);
int minute = cal.get(Calendar.MINUTE);
// 12-hour format
int hour = cal.get(Calendar.HOUR);
// 24-hour format
int hourofday = cal.get(Calendar.HOUR_OF_DAY);
Same goes for the date, as follows:
Calendar cal = Calendar.getInstance();
int dayofyear = cal.get(Calendar.DAY_OF_YEAR);
int year = cal.get(Calendar.YEAR);
int dayofweek = cal.get(Calendar.DAY_OF_WEEK);
int dayofmonth = cal.get(Calendar.DAY_OF_MONTH);

SimpleDateFormat databaseDateTimeFormate = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
SimpleDateFormat databaseDateFormate = new SimpleDateFormat("yyyy-MM-dd");
SimpleDateFormat sdf1 = new SimpleDateFormat("dd.MM.yy");
SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy.MM.dd G 'at' hh:mm:ss z");
SimpleDateFormat sdf3 = new SimpleDateFormat("EEE, MMM d, ''yy");
SimpleDateFormat sdf4 = new SimpleDateFormat("h:mm a");
SimpleDateFormat sdf5 = new SimpleDateFormat("h:mm");
SimpleDateFormat sdf6 = new SimpleDateFormat("H:mm:ss:SSS");
SimpleDateFormat sdf7 = new SimpleDateFormat("K:mm a,z");
SimpleDateFormat sdf8 = new SimpleDateFormat("yyyy.MMMMM.dd GGG hh:mm aaa");
String currentDateandTime = databaseDateTimeFormate.format(new Date()); //2009-06-30 08:29:36
String currentDateandTime = databaseDateFormate.format(new Date()); //2009-06-30
String currentDateandTime = sdf1.format(new Date()); //30.06.09
String currentDateandTime = sdf2.format(new Date()); //2009.06.30 AD at 08:29:36 PDT
String currentDateandTime = sdf3.format(new Date()); //Tue, Jun 30, '09
String currentDateandTime = sdf4.format(new Date()); //8:29 PM
String currentDateandTime = sdf5.format(new Date()); //8:29
String currentDateandTime = sdf6.format(new Date()); //8:28:36:249
String currentDateandTime = sdf7.format(new Date()); //8:29 AM,PDT
String currentDateandTime = sdf8.format(new Date()); //2009.June.30 AD 08:29 AM
Date format Patterns
G Era designator (before christ, after christ)
y Year (e.g. 12 or 2012). Use either yy or yyyy.
M Month in year. Number of M's determine length of format (e.g. MM, MMM or MMMMM)
d Day in month. Number of d's determine length of format (e.g. d or dd)
h Hour of day, 1-12 (AM / PM) (normally hh)
H Hour of day, 0-23 (normally HH)
m Minute in hour, 0-59 (normally mm)
s Second in minute, 0-59 (normally ss)
S Millisecond in second, 0-999 (normally SSS)
E Day in week (e.g Monday, Tuesday etc.)
D Day in year (1-366)
F Day of week in month (e.g. 1st Thursday of December)
w Week in year (1-53)
W Week in month (0-5)
a AM / PM marker
k Hour in day (1-24, unlike HH's 0-23)
K Hour in day, AM / PM (0-11)
z Time Zone

For the current date and time with format, use:
In Java
Calendar c = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String strDate = sdf.format(c.getTime());
Log.d("Date", "DATE: " + strDate)
In Kotlin
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
val current = LocalDateTime.now()
val formatter = DateTimeFormatter.ofPattern("dd.MM.yyyy. HH:mm:ss")
var myDate: String = current.format(formatter)
Log.d("Date", "DATE: " + myDate)
} else {
var date = Date()
val formatter = SimpleDateFormat("MMM dd yyyy HH:mma")
val myDate: String = formatter.format(date)
Log.d("Date", "DATE: " + myDate)
}
Date formatter patterns
"yyyy.MM.dd G 'at' HH:mm:ss z" ---- 2001.07.04 AD at 12:08:56 PDT
"hh 'o''clock' a, zzzz" ----------- 12 o'clock PM, Pacific Daylight Time
"EEE, d MMM yyyy HH:mm:ss Z"------- Wed, 4 Jul 2001 12:08:56 -0700
"yyyy-MM-dd'T'HH:mm:ss.SSSZ"------- 2001-07-04T12:08:56.235-0700
"yyMMddHHmmssZ"-------------------- 010704120856-0700
"K:mm a, z" ----------------------- 0:08 PM, PDT
"h:mm a" -------------------------- 12:08 PM
"EEE, MMM d, ''yy" ---------------- Wed, Jul 4, '01

final Calendar c = Calendar.getInstance();
int mYear = c.get(Calendar.YEAR);
int mMonth = c.get(Calendar.MONTH);
int mDay = c.get(Calendar.DAY_OF_MONTH);
textView.setText("" + mDay + "-" + mMonth + "-" + mYear);

This is a method that will be useful to get date and time:
private String getDate(){
DateFormat dfDate = new SimpleDateFormat("yyyy/MM/dd");
String date=dfDate.format(Calendar.getInstance().getTime());
DateFormat dfTime = new SimpleDateFormat("HH:mm");
String time = dfTime.format(Calendar.getInstance().getTime());
return date + " " + time;
}
You can call this method and get the current date and time values:
2017/01//09 19:23

If you need the current date:
Calendar cc = Calendar.getInstance();
int year = cc.get(Calendar.YEAR);
int month = cc.get(Calendar.MONTH);
int mDay = cc.get(Calendar.DAY_OF_MONTH);
System.out.println("Date", year + ":" + month + ":" + mDay);
If you need the current time:
int mHour = cc.get(Calendar.HOUR_OF_DAY);
int mMinute = cc.get(Calendar.MINUTE);
System.out.println("time_format" + String.format("%02d:%02d", mHour , mMinute));

You can also use android.os.SystemClock.
For example SystemClock.elapsedRealtime() will give you more accurate time readings when the phone is asleep.

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
System.out.println("time => " + dateFormat.format(cal.getTime()));
String time_str = dateFormat.format(cal.getTime());
String[] s = time_str.split(" ");
for (int i = 0; i < s.length; i++) {
System.out.println("date => " + s[i]);
}
int year_sys = Integer.parseInt(s[0].split("/")[0]);
int month_sys = Integer.parseInt(s[0].split("/")[1]);
int day_sys = Integer.parseInt(s[0].split("/")[2]);
int hour_sys = Integer.parseInt(s[1].split(":")[0]);
int min_sys = Integer.parseInt(s[1].split(":")[1]);
System.out.println("year_sys => " + year_sys);
System.out.println("month_sys => " + month_sys);
System.out.println("day_sys => " + day_sys);
System.out.println("hour_sys => " + hour_sys);
System.out.println("min_sys => " + min_sys);

Use:
Time time = new Time();
time.setToNow();
System.out.println("time: " + time.hour + ":" + time.minute);
This will give you, for example, "12:32".
Remember to import android.text.format.Time;.

You can simply use the following code:
DateFormat df = new SimpleDateFormat("HH:mm"); // Format time
String time = df.format(Calendar.getInstance().getTime());
DateFormat df1 = new SimpleDateFormat("yyyy/MM/dd"); // Format date
String date = df1.format(Calendar.getInstance().getTime());

Current time and date in Android with the format
Calendar c = Calendar.getInstance();
System.out.println("Current dateTime => " + c.getTime());
SimpleDateFormat df = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss a");
String formattedDate = df.format(c.getTime());
System.out.println("Format dateTime => " + formattedDate);
Output
I/System.out: Current dateTime => Wed Feb 26 02:58:17 GMT+05:30 2020
I/System.out: Format dateTime => 26-02-2020 02:58:17 AM

For a customized time and date format:
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZZZZZ",Locale.ENGLISH);
String cDateTime = dateFormat.format(new Date());
The output is in this format:
2015-06-18T10:15:56-05:00

Time now = new Time();
now.setToNow();
Try this works for me as well.

You can obtain the date by using:
Time t = new Time(Time.getCurrentTimezone());
t.setToNow();
String date = t.format("%Y/%m/%d");
This will give you a result in a nice form, as in this example: "2014/02/09".

Well, I had problems with some answers by the API, so I fused this code:
Time t = new Time(Time.getCurrentTimezone());
t.setToNow();
String date1 = t.format("%Y/%m/%d");
Date date = new Date(System.currentTimeMillis());
SimpleDateFormat dateFormat = new SimpleDateFormat("hh:mm aa", Locale.ENGLISH);
String var = dateFormat.format(date);
String horafecha = var+ " - " + date1;
tvTime.setText(horafecha);
Output:
03:25 PM - 2017/10/03

Java
Long date=System.currentTimeMillis();
SimpleDateFormat dateFormat =new SimpleDateFormat("dd / MMMM / yyyy - HH:mm", Locale.getDefault());
String dateStr = dateFormat.format(date);
Kotlin
date if milliseconds and 13 digits(hex to date)
val date=System.currentTimeMillis() //here the date comes in 13 digits
val dtlong = Date(date)
val sdfdate = SimpleDateFormat(pattern, Locale.getDefault()).format(dtlong)
Date Formatter
"dd / MMMM / yyyy - HH:mm" -> 29 / April / 2022 - 12:03
"dd / MM / yyyy" -> 29 / 03 / 2022
"dd / MMM / yyyy" -> 29 / Mar / 2022 (shortens the month)
"EEE, d MMM yyyy HH:mm:ss" -> Wed, 4 Jul 2022 12:08:56

Date todayDate = new Date();
todayDate.getDay();
todayDate.getHours();
todayDate.getMinutes();
todayDate.getMonth();
todayDate.getTime();

Try This
String mytime = (DateFormat.format("dd-MM-yyyy hh:mm:ss", new java.util.Date()).toString());

You should use the Calender class according to the new API. The Date class is deprecated now.
Calendar cal = Calendar.getInstance();
String date = "" + cal.get(Calendar.DATE) + "-" + (cal.get(Calendar.MONTH)+1) + "-" + cal.get(Calendar.YEAR);
String time = "" + cal.get(Calendar.HOUR_OF_DAY) + ":" + cal.get(Calendar.MINUTE);

The below method will return the current date and time in a String, Use a different time zone according to your actual time zone. I've used GMT.
public static String GetToday(){
Date presentTime_Date = Calendar.getInstance().getTime();
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
return dateFormat.format(presentTime_Date);
}

OffsetDateTime to Date Android

I am getting an OffsetDateTime from our backend in a String format like this:
"2017-07-15T10:52:59Z"
I am trying to parse this String to a Android Date:
private SimpleDateFormat mSimpleDateFormat;
private static final String DATE_FORMAT_PATTERN = "yyyy-MM-dd'T'HH:mm:ss";
mSimpleDateFormat = new SimpleDateFormat(DATE_FORMAT_PATTERN, Locale.getDefault());
Date newDate = null;
String dateString = notice.getCreated();
try {
newDate = mSimpleDateFormat.parse(dateString);
} catch (ParseException e) {
LogHelper.showExceptionLog(MyClass.class, e);
}
It always throws:
Unparseable date: "2017-07-15T10:52:59Z"

To parse the Z (which is the UTC designator) you must use the X pattern (as explained in javadoc):
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX");
String dateString = "2017-07-15T10:52:59Z";
Date newDate = mSimpleDateFormat.parse(dateString);
If you use just yyyy-MM-dd'T'HH:mm:ss as a pattern, SimpleDateFormat will use the system's default timezone and ignore the Z, giving incorrect results: it'll parse the date/time as 10:52 in the default timezone, which can be different to 10:52 in UTC. By using the X pattern, you get the correct result.
I also removed the Locale because this formatter is not dealing with any locale-sensitive information (like month and day of week names), so it doesn't affect the parsing in this case (and SimpleDateFormat already uses the default locale if you don't specify one).
PS: the X pattern was introduced in JDK 7. If you're using and older version, it won't be available. In this case, you can set the UTC as a timezone of the formatter:
SimpleDateFormat mSimpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
mSimpleDateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
Obviously this code is assuming that the input is always in UTC (with Z in the end).
Java new Date/Time API
The old classes (Date, Calendar and SimpleDateFormat) have lots of problems and design issues, and they're being replaced by the new APIs.
For Android, you can use the ThreeTen Backport, a great backport for Java 8's new date/time classes. To make it work, you'll also need ThreeTenABP (more on how to use it here).
As the input string is in ISO 8601 format, you can easily parse it to a org.threeten.bp.OffsetDateTime:
String dateString = "2017-07-15T10:52:59Z";
OffsetDateTime odt = OffsetDateTime.parse(dateString);
You can then convert this to a java.util.Date easily, using the org.threeten.bp.DateTimeUtils class:
Date date = DateTimeUtils.toDate(odt.toInstant());
If the input is always in UTC (always with the Z in the end), you can also use a org.threeten.bp.Instant:
String dateString = "2017-07-15T10:52:59Z";
Instant instant = Instant.parse(dateString);
Date date = DateTimeUtils.toDate(instant);
The only difference is that Instant only parses UTC inputs (ending with Z) and OffsetDateTime accepts any valid UTC offset (like -03:00 or +05:30).

Getting Current date and time

I tried to access current datetime in android application as follows :
Calendar c = Calendar.getInstance();
int seconds = c.get(Calendar.SECOND);
//long time = System.currentTimeMillis();
Date date2 = new Date(seconds);
Log.d(">>>>>>>Current Date : ",""+date2);
It gives me date and time with the year 1970 as follows :
>>>>>>>Current Date :﹕ Thu Jan 01 05:30:00 GMT+05:30 1970
but, It should be 2015 instead of 1970.
What the problem is ?
I have solved above problem from solution provided. Atually, I am generating notification as the datetime value from the databse matches to the current datetime value. but, it does not generating notification.
My code is as follows :
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
doAsynchTask = new TimerTask() {
#Override
public void run() {
Log.d("Timer Task Background", "Timer task background");
Calendar c = Calendar.getInstance();
c.setTime(new Date());
long time = System.currentTimeMillis();
Date dateCurrent = new Date(time);
Log.d(">>>>>>>Current Date : ", "" + dateCurrent);
getListData();
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd hh:mm a");
Date dateFromDatabase;
for (int i = 0; i < remiderList.size(); i++) {
try {
System.out.print("+++" + remiderList.get(i).toString());
dateFromDatabase = formatter.parse(remiderList.get(i).toString());
Log.d(">>>>>Database date : ", "" + dateFromDatabase);
if (dateCurrent.equals(dateFromDatabase)) {
Toast.makeText(getApplicationContext(), "Date matched", Toast.LENGTH_LONG).show();
displayNotification();
}
} catch (ParseException e) {
e.printStackTrace();
}
}
}
};
timer.schedule(doAsynchTask, 0, 1000);
}
public void displayNotification() {
Notification.Builder builder = new Notification.Builder(MyRemiderService.this);
Intent intent1 = new Intent(this.getApplicationContext(),
HomeActivity.class);
Notification notification = new Notification(R.drawable.notification_template_icon_bg,
"This is a test message!", System.currentTimeMillis());
intent1.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP
| Intent.FLAG_ACTIVITY_CLEAR_TOP);
PendingIntent pendingNotificationIntent = PendingIntent.getActivity(
this.getApplicationContext(), 0, intent1,
PendingIntent.FLAG_UPDATE_CURRENT);
builder.setSmallIcon(R.drawable.abc_ic_ab_back_mtrl_am_alpha)
.setContentTitle("ContentTitle").setContentText("this for test massage")
.setContentIntent(pendingNotificationIntent);
notification = builder.getNotification();
notification.flags |= Notification.FLAG_AUTO_CANCEL;
/* notification.setLatestEventInfo(this.getApplicationContext(),
"AlarmManagerDemo", "This is a test message!",
pendingNotificationIntent);*/
mManager.notify(0, notification);
}
#Override
public void onDestroy() {
super.onDestroy();
}
public void getListData() {
remiderList = dbHelper.getAllRemiders();
}
I have checked both the values in Logcat as follows :
09-15 17:50:00.629 17915-17927/? D/>>>>>>>Current Date :﹕ Tue Sep 15 17:50:00 GMT+05:30 2015
09-15 17:50:00.637 17915-17927/? D/>>>>>Database date :﹕ Tue Sep 15 17:50:00 GMT+05:30 2015

You have not set current date in calender object.
Calendar c = Calendar.getInstance();
c.setTime(new Date());
//Calendar.SECOND will return only seconds from the date
//int seconds = c.get(Calendar.SECOND);
long time = c.getTime();
Date date2 = new Date(time);
Log.d(">>>>>>>Current Date : ",""+date2);
You can use SimpleDateFormat class to format the dates as follow
SimpleDateFormat format = new SimpleDateFormat("dd-MM-yyyy hh:mm:ss");
System.out.println(format.format(new Date()));

try this
private String getCurrentDateAndTime() {
SimpleDateFormat simple = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ENGLISH);
return simple.format(new Date());
}

Avoid old date-time classes
You are using the old date-time classes bundled with the earliest versions of Java such as java.util.Date/.Calendar. They have proven to be poorly designed, confusing, and troublesome. Avoid them.
Among the many points of confusion is that a java.util.Date represents a calendar date and a time-of-day while a java.sql.Date pretends to represent only a date without any time-of-day although it does actually have a time-of-day just set to zeros (00:00:00.0).
java.time
The old date-time classes have been supplanted by the java.time framework. See Tutorial.
Java 8 and later: The java.time framework is built-in.
Java 7 & 6: Use the backport of java.time.
Android: Use this wrapped version of that backport.
java.sql
Eventually we should see JDBC drivers updated to deal with java.time types directly. Until then, we still need the java.sql types for getting data in/out of databases. But immediately call the new conversion methods added to the old classes to move into java.time types.
Instant
An Instant is a moment on the timeline in UTC with resolution up to nanoseconds.
java.sql.Timestamp ts = myResultSet.getTimestamp( x );
Instant instant = ts.toInstant();
LocalDate
If you are trying to compare the date-portion of that date time to today’s date, use the LocalDate class. This class truly represents a date-only value without time-of-day and without time zone.
Time Zone
Note that a time zone is crucial to determining dates, as the date may vary around the world by time zone for any given moment. So before extracting the LocalDate we need to apply a time zone (ZoneId) to get a ZonedDateTime. If you omit the time zone your JVM’s current default time zone is implicitly applied. Better to specify explicitly the desired/expected time zone.
ZoneId zoneId = ZoneId.of( "America/Montreal" ); // Or "Asia/Kolkata", "Europe/Paris", and so on.
ZonedDateTime zdt = ZonedDateTime.ofInstant( instant , zoneId );
LocalDate today = LocalDate.now( zoneId );
if( today.isEqual( zdt.toLocalDate() ) {
…
}
Notice that nowhere in that code did we use Strings; all date-time objects instead.
Formatting Strings
To generate a String as a textual representation of the date-time value, you can call the toString methods to get text formatted using the ISO 8601 standard. Or specify your own formatting pattern. Better yet, let java.time do the work of localizing automatically. Specify a Locale for a human language (English, French, etc.) to use in translating the name of day/month and such.
DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDateTime( FormatStyle.MEDIUM );
String output = zdt.format( formatter.withLocale( Locale.US ) ); // Or Locale.CANADA_FRENCH and so on.

Android Timezone Ids are not matching with System Timezone Ids issue

I am working on timezones concept in Android.
I want to change the timezone of the Android tablet by taking the timezone from the App Variable in the application. I am getting the System TimeZones as the variable value i.e like
Dateline Standard Time
UTC-11
Samoa Standard Time
Hawaiian Standard Time
Alaskan Standard Time
Pacific Standard Time (Mexico)
Pacific Standard Time
US Mountain Standard Time
Mountain Standard Time (Mexico)
Mountain Standard Time
Central America Standard Time
Central Standard Time
Central Standard Time (Mexico)
Canada Central Standard Time
SA Pacific Standard Time
From Android case, I am getting Timezone Id's like
Africa/Harare
Africa/Johannesburg
Africa/Kigali
Africa/Lubumbashi
Africa/Lusaka
Africa/Maputo
Africa/Maseru
Africa/Mbabane
Africa/Tripoli
Asia/Amman
Asia/Beirut
Asia/Istanbul
Asia/Jerusalem
Asia/Nicosia
Asia/Tel_Aviv
CAT
EET
Egypt
Etc/GMT-2
Europe/Chisinau
Europe/Helsinki
and my code is
if (mCalendar != null) {
mCalendar = Calendar.getInstance();
}
else
{
String[] allTimeZones = TimeZone.getAvailableIDs();
Arrays.sort(allTimeZones);
for (int i = 0; i < allTimeZones.length; i++) {
System.out.println(allTimeZones[i]);
}
TimeZone tz = TimeZone.getTimeZone(String.valueOf(Jordan Standard Time));
mCalendar = Calendar.getInstance(tz);
String name = tz.getID();
System.out.println("TimeZone "+tz.getDisplayName(false, TimeZone.SHORT)+" Timezon id :: " + name);
}
As 'Jordan Standard Time' is variable from application is not like Timezone of tablet available Id's, Timezone is not changing.
If I replace the Timezone with 'Africa/Tripoli' manually, the timezone is replacing with this one.
My issue now is I would like to convert the system timezones to Tablet Timezone Ids and display it in Android Application.

plz use this function that is display GMT Time display if you change timezone from you android phone.
public static String GetDateForGMTDate(String dateString) {
SimpleDateFormat formatter = new SimpleDateFormat(
"yyyy-mm-dd");
SimpleDateFormat formatter1 = new SimpleDateFormat(
"yyyy-mm-dd");
Date date = null;
try {
date = formatter.parse(dateString);
System.out.println(date);
System.out.println(formatter.format(date));
Calendar cal = Calendar.getInstance();
cal.setTime(date);
Log.i("Time zone", "gettime=" + cal.getTime());
cal.add(Calendar.MINUTE, (-1 * getTimeZoneDifference()));
Log.i("Time zone", "after gmt +gettime=" + cal.getTime());
date = cal.getTime();
} catch (ParseException e) {
e.printStackTrace();
}
return formatter1.format(date);
}
public static final int getTimeZoneDifference() {
long currentTime = System.currentTimeMillis();
int gmtcurrentOffset = TimeZone.getDefault().getOffset(currentTime);
int gmtOffset = TimeZone.getTimeZone("GMT").getOffset(currentTime);
int minuteDifference = (((gmtOffset - gmtcurrentOffset) / 1000) / 60);
return minuteDifference;
}
use 1st function and pass any date with yyy-mm-dd formate as a string. and that function will return gmt formate real date-time.
i already use it.
its working fine.i hope its useful to you.

converting long string to date [duplicate]

This question already has answers here:
Unfortunately MyApp has stopped. How can I solve this?
(23 answers)
Convert UTC Epoch to local date
(16 answers)
How to convert String to long in Java?
(10 answers)
Closed 1 year ago.
I am getting date value from DB as a long value. I am converting this to string to use parse function. Given below is my code
Date date1 = new SimpleDateFormat("MM/dd/yyyy").parse(strDate1);
But the app is crashing when this code is executing.it will successfully execute if the
strDate1="12/30/2012".
But i am having this value as "12302012235"(pzudo value).
How can i do this?
edit:
i am saving date value to DB as INTEGER. from DB i am getting this value and converting to string.this is the actual strDate1 value
strDate1="1346524199000"

Try the following code segment:
Calendar c = Calendar.getInstance();
c.setTimeInMillis(Long.parseLong(val));
Date d = (Date) c.getTime();
SimpleDateFormat format = new SimpleDateFormat("dd/MM/yyyy");
String time = format.format(d);//this variable time contains the time in the format of "day/month/year".

Try this,
SimpleDateFormat dateFormat=new SimpleDateFormat("yyyy-MM-dd");
Date dateD=new Date();
dateD.setTime(LongTime);
date=dateFormat.format(dateD);

Java 8, Convert milliseconds long to Date as String by given date format pattern. If you have a long milliseconds and want to convert them into date string at specifies time zone and pattern, then you can use it:-
dateInMs is a long value of DateTime.
DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")
.format(Instant.ofEpochMilli(dateInMs).atZone(ZoneId.of("Europe/London")))

java.time
The java.util date-time API and their formatting API, SimpleDateFormat are outdated and error-prone. It is recommended to stop using them completely and switch to the modern date-time API* .
Using modern date-time API:
import java.time.Instant;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Date;
import java.util.Locale;
public class Main {
public static void main(String[] args) {
long input = 12302012235L;
// Get Instant from input
Instant instant = Instant.ofEpochMilli(input);
System.out.println(instant);
// Convert Instant to ZonedDateTime by applying time-zone
// Change ZoneId as applicable e.g. ZoneId.of("Asia/Dubai")
ZonedDateTime zdt = instant.atZone(ZoneId.systemDefault());
System.out.println(zdt);
// Format ZonedDateTime as desired
// Check https://stackoverflow.com/a/65928023/10819573 to learn more about 'u'
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("MM/dd/uuuu", Locale.ENGLISH);
String formatted = dtf.format(zdt);
System.out.println(formatted);
// If at all, you need java.util.Date
Date date = Date.from(instant);
}
}
Output:
1970-05-23T09:13:32.235Z
1970-05-23T10:13:32.235+01:00[Europe/London]
05/23/1970
Learn more about the modern date-time API from Trail: Date Time.
* For any reason, if you have to stick to Java 6 or Java 7, you can use ThreeTen-Backport which backports most of the java.time functionality to Java 6 & 7. If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project.

You can try following code:
private Date getGMTDate(long date) {
SimpleDateFormat dateFormatGmt = new SimpleDateFormat(
"yyyy-MMM-dd HH:mm:ss");
dateFormatGmt.setTimeZone(TimeZone.getTimeZone("GMT"));
SimpleDateFormat dateFormatLocal = new SimpleDateFormat(
"yyyy-MMM-dd HH:mm:ss");
Date temp = new Date(date);
try {
return dateFormatLocal.parse(dateFormatGmt.format(temp));
} catch (ParseException e) {
e.printStackTrace();
}
return temp;
}
I hope this will help you.

Try this
Date date1 = new SimpleDateFormat("MMddyyyySSS").parse(strDate1);
Hope it will works for 12302012235 , but i assume 235 is millisec.

i got the answer.actually i wanted to convert the string to date only for comparing the values.since i am getting the value as long i directly used the compareTo function to do this.avoided the conversion of long to string and string to date conversion.thank you all for support.

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.