How to get correct Date and time for my application,when wrong android device date and time.need to source .
please help me.
thank you all!
You may need to use a custom NITZ or NTP Library
http://groups.google.com/group/android-developers/browse_thread/thread/d5ce3bcfe17e272b?pli=1
So just a heads up that Android uses NITZ events provided by a carrier to properly set the system date and time. Android also falls-back to network NTP automatically when no cellular network is available.
http://en.wikipedia.org/wiki/NITZ
The time provided by currentTimeMillis() will typically be the best available time, and it's what all of the services on the device use, like Calendar and Alarm Clock.
However
However the NTP API isn't somewhere that Java code can access, which means we're back to using an existing Java NTP/SNTP client library if we want an accurate time regardless of whether we are on a network that is NITZ capable.
Java NTP library
You can find a naive implementation of a Java NTP Library from
support.ntp.org
first you try to get the current time zone and then you get date and time of current time zone
Calendar cal = Calendar.getInstance();
TimeZone tz = cal.getTimeZone();
Log.d("Time zone","="+tz.getDisplayName());
public String getTime(String timezone) {
Calendar c = Calendar.getInstance();
c.setTimeZone(TimeZone.getTimeZone(timezone));
Date date = c.getTime();
SimpleDateFormat df = new SimpleDateFormat("dd/MM/yyyy");
String strDate = df.format(date);
return c.getTime().toString();
}
Related
I tried:
TimeZone.getDefault();
I tried:
Calendar mCalendar = new GregorianCalendar();
TimeZone mTimeZone = mCalendar.getTimeZone();
I tried:
Calendar c = Calendar.getInstance();
mTimeZone = c.getTimeZone();
No matter what I try... it gives me a default of 0 and GMT. My app just cannot seem to get the time zone (it should read -4 or ET, i.e. eastern USA time zones)
The strange thing is... my clock displays the correct time on my phone.
the "use automatic time zone" is checked in settings of my android device.
So why can't I get the local time in my app? how does the Android clock able to achieve this but not me?
I have checked online and cant seem to find anything. Is there at least a way to sync with the clock app and receive it's time to display on my app as well? Is there ANY way to get the correct time on my app?
System.getMilliseconds() return the time since epoch, which would only function as the current time in areas that use GMT. (As long as what you are using doesn't make it's own conversion)
To get local time in milliseconds since epoch, you can use this function:
// Kotlin
fun getLocalTime(): Long
{
val currentDate = Calendar.getInstance()
return currentDate.timeInMillis + TimeZone.getDefault().getOffset(currentDate.timeInMillis)
}
Which in Java would probably look like this:
// Java
static long getLocalTime()
{
Calendar currentDate = Calendar.getInstance();
return currentDate.getTimeInMillis() + TimeZone.getDefault().getOffset(currentDate.getTimeInMillis());
}
The function takes the time since epoch and adds to it the timezone offset of the phone's local timezone.
When I create a new instance of LocalDateTime and try to get the current hour, it is off by exactly 4 hours.
For example my code will be as follows:
LocalDateTime mReminderTime = new LocalDateTime();
int mHourOfDay = mReminderTime.getHourOfDay();
The system time on the phone/tablet will be 19:00 while mHourOfDay will be 23:00. I have been testing these on physical devices.
I have also tried the following code with the same results:
LocalDateTime mReminderTime = LocalDateTime.now();
int mHourOfDay = mReminderTime.getHourOfDay();
My timezone is EST, which is -4:00 of GMT. I believe this is exactly the issue. The LocalDateTime is instantiating at 0:00 GMT causing mHourOfDay to be precisely 4 hours ahead of the system time.
My question: How do I get the LocalDateTime to initialize at EST via detecting the current timezone of the device? I don't want to set LocalDateTime to specifically use -4:00 GMT in case the user changes timezones. Right now I have a workaround solution using the Calendar as follows:
Calendar cal = Calendar.getInstance();
mReminderTime = new LocalDateTime(cal);
I was hoping to rely fully on Joda-Time, thus I wanted a solution that avoids the Calendar. If it helps, I am using this library to import Joda-Time into my project: https://github.com/dlew/joda-time-android
i am currently using the following line to achieve the time: System.currentTimeInMilis.
I have noticed it doesn't consider time zones,or does it not match the android phone it self by the time, while on the emulator it does match.s
so is there another type of way to get the android clock it self? so when the user adjusts he's phones built in clock, it affects it too?
float getTime()
{
Calendar cal = new GregorianCalendar();
cal.setTimeInMillis(System.currentTimeMillis());
cal.setTimeZone(TimeZone.getDefault());
return cal.getTimeInMillis();
}
Read the documentation of currentTimeMillis. It has a time zone, which happens to be UTC (which is the default for Unix time stamps).
If you want to convert it to a different time zone you can make use of the Java Calendar and TimeZone classes:
Calendar cal = new GregorianCalendar();
cal.setTimeInMillis(System.currentTimeMillis());
cal.setTimeZone(TimeZone.getDefault());
Alternatively you can just create a new GregorianCalendar instance. By default its TimeZone will match the local one (as set on the device) and the time will be set to "now".
There are also other ways for retrieving the current time according the current time zone and locale as string. Take a look at DateUtils.
EDIT Explaining the usage of Calendar
Read the documentation for Calendar.getTimeMillis(). That method returns the Unix time stamp again which happens to have the time zone UTC.
You have to use the Calendar.get() method instead for getting the correct values. See following example for getting the current hour in the correct time zone via your calendar object:
int hour = cal.get(Calendar.HOUR_OF_HAY);
Read the documentation of Calendar. There are plenty of fields like HOUR_OF_DAY which help you getting values like the year, month, minute, seconds etc.
I have an issue of converting selected hours and minutes to different time zones of countries.
Supposing if i select 10 am in India then i want to know at 10 am in india what will be the time in USA/New york and Tokyo.and Vice versa.
Any help is appreciable...
Thank you
please find the sollution below :
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy hh:mma");
TimeZone timezone = TimeZone.getDefault();
TimeZone utcTimeZone = TimeZone.getTimeZone("UTC");
Date d = new Date();
sdf.setTimeZone(timezone);
String strtime = sdf.format(d);
Log.e("str time gmt ",strtime);
sdf.setTimeZone(utcTimeZone);
strtime = sdf.format(d);
Log.e("str time utc ",strtime);
i think this will solve your problem
You can probably use Joda Time - Java date and time API. You can get the DateTimeZone depending on the Canonical ID defined in the Joda Time,
DateTimeZone zone = DateTimeZone.forID("Asia/Kolkata");
Joda Time has a complete list of Canonical ID from where you can get TimeZone depending on the Canonical ID.
So, if you want to get the local time in New York at this very moment, you would do the following
// get current moment in default time zone
DateTime dt = new DateTime();
// translate to New York local time
DateTime dtNewYork = dt.withZone(DateTimeZone.forID("America/New_York"));
For getting more idea you can refer Changing TimeZone
Try using Joda-Time library
check the org.joda.time.DateTimeZone class
Here is the API documentation for the same.
you can also get it using , Here no external API is needed
DateFormat format = new SimpleDateFormat("MMMMM d, yyyy, h:mm a");
TimeZone utc = TimeZone.getTimeZone("America/New_York");
System.out.println(utc.getID());
GregorianCalendar gc = new GregorianCalendar(utc);
Date now = gc.getTime();
System.out.println(format.format(now));
you can see more time zone on this Link
Output
America/New_York
December 29, 2012, 11:04 AM
If you don't know city name then you can also use it by Zone name as follow
DateFormat format = new SimpleDateFormat("MMMMM d, yyyy, h:mm a");
TimeZone cst = TimeZone.getTimeZone("US/Eastern");
System.out.println(cst.getID());
GregorianCalendar gc = new GregorianCalendar(cst);
Date now = gc.getTime();
format.setTimeZone(cst);
System.out.println(format.format(now))
Output
US/Eastern
December 29, 2012, 12:38 AM
Not really sure about the solution I'm going to provide but I think you can try it. GMT (Greenwich Mean Time) is a standard. I think you can keep it as a base and calculate the desired time. GMT standard is easily available too.
For example: While installing an OS like Windows XP or Windows 7, we select the time from a drop down menu. My point is, keeping this as the base, you can find the difference between the time zones in NY-US and Tokyo-Japan or vice versa as you desire it.
Hope this helps.
How can I construct a Calendar object using getInstance(TimeZone) to use the device's TimeZone?
According to this issue, just using:
Calendar calendar = Calendar.getInstance();
will give you an instance in the user's default time zone (as per their settings). You can determine the time zone from the calendar with:
TimeZone zone = calendar.getTimeZone();
Other posts have suggested that using TimeZone.getDefault() does not give this user-default time zone - I don't know about that personally, but it's another option to look into.