Develop Reference

Getting Time Until a Date in Android

I am using a Date and Time Dialog to get a Date and Time for an Event Specifed by the User. That data is the Converted by doing the following:
int yearE = Integer.valueOf(evntDate.split("/")[2]);
int monthE = Integer.valueOf(evntDate.split("/")[1]);
int dayE = Integer.valueOf(evntDate.split("/")[0]);
int hour = Integer.valueOf(evntTm.split(":")[0]);
int min = Integer.valueOf(evntTm.split(":")[1]);
With the Values of:
eventDate = "3/5/2015";
eventTime = "13:2";
I then get that data and COnvert it into Milliseconds and Store that in the Database:
newCalendar.set(yearE, monthE, dayE,hour, min, 0);
startTime = newCalendar.getTimeInMillis();
...
When I load the Info from the Database, I try to calculate the amount of time left until the Specified date. So I do the following:
Long timeL = Long.valueOf(time);
Calendar eventDay = Calendar.getInstance();
eventDay.setTimeInMillis(timeL);
Calendar today = Calendar.getInstance();
long diff = eventDay.getTimeInMillis() - today.getTimeInMillis();
// CONVERT:
int seconds = (int) TimeUnit.MILLISECONDS.toSeconds(diff);
int minutes = (int) TimeUnit.MILLISECONDS.toMinutes(diff);
int hours = (int) TimeUnit.MILLISECONDS.toHours(diff);
int days = (int) TimeUnit.MILLISECONDS.toDays(diff);
...
When I log the above data, the days are usually around 30-32 and the rest of the data is incorrect as well. What am I doing wrong? Or what are some alternatives?

Consider using the Joda time library instead of Calendar, it's much easier to work with.
As you're on android, I'll assume that you're using gradle, so go ahead and drop this in your dependencies
compile 'joda-time:joda-time:2.3'
I've created a small psvm to demo how you can use it
import org.joda.time.DateTime;
import org.joda.time.Period;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.PeriodFormat;
import static java.lang.String.format;
public class DateTimeDemo {
public static void main(String[] args) {
// Your date/time values, I'll assume you missed a digit off the time ;)
String eventDate = "3/5/2015";
String eventTime = "13:20";
// convert these to a DateTime object
DateTime targetDateTime = DateTime.parse(format("%s %s", eventDate, eventTime), DateTimeFormat.forPattern("dd/MM/yyyy HH:mm"));
// print out the millis, or in your case, save it to DB
System.out.println("targetDateTime in millis is " + targetDateTime.getMillis());
// grab a timestamp
DateTime now = DateTime.now();
// print it out, just for demo
System.out.println("millis for now is " + now.getMillis());
// create a period object between the two
Period period = new Period(now, targetDateTime);
// print out each part
System.out.println("seconds " + period.getSeconds());
System.out.println("hours " + period.getHours());
System.out.println("months " + period.getMonths());
// convert the period to a printable String
String prettyPeriod = PeriodFormat.getDefault().print(period);
// write it out!
System.out.println(prettyPeriod);
}
}
Output is
targetDateTime in millis is 1430623200000
millis for now is 1425527593584
seconds 46
hours 22
months 1
1 month, 3 weeks, 6 days, 22 hours, 26 minutes, 46 seconds and 416 milliseconds

You can use Joda for that.
long dbTime = 1425525415837L;
Period period = new Period( dbTime, System.currentTimeMillis() );
String formatted = PeriodFormat.getDefault().print(period);
System.out.println( formatted );
If you want more control of the format use PeriodFormatter.
If you want to get the seconds, minutes, hours, etc. and not just print them, you can use the various available methods. For example:
period.getSeconds();
period.getHours();
period.getMonths();
More formatting options are described in this question.

Are you expecting to see something similar:
seconds = 36 (always less than 60)
minutes = 12 (always less that 60)
hours = 17 (always less than 24)
days = 45 (always less that 31 if # of months is used, else < 366 if # of years is used)
...
...
from:
// CONVERT:
int seconds = (int) TimeUnit.MILLISECONDS.toSeconds(diff);
int minutes = (int) TimeUnit.MILLISECONDS.toMinutes(diff);
int hours = (int) TimeUnit.MILLISECONDS.toHours(diff);
int days = (int) TimeUnit.MILLISECONDS.toDays(diff);
Its a logical error then. TimeUnit.MILLISECONDS.toXXXX(long) converts the whole time-difference into the specified units. This is of no value to you.
As an example, say you set the event's date to 32 days from now - and time to 13:15.
Millisecond difference =
2764800000 (32 days in millis)
+ 46800000 (13 hours in millis)
+ 900000 (15 minutes in millis)
= 2812500000
Using this time-difference, the following log:
int seconds = (int) TimeUnit.MILLISECONDS.toSeconds(diff);
int minutes = (int) TimeUnit.MILLISECONDS.toMinutes(diff);
int hours = (int) TimeUnit.MILLISECONDS.toHours(diff);
int days = (int) TimeUnit.MILLISECONDS.toDays(diff);
produces:
Seconds left: 2812500
Minutes left: 46875
Hours left: 781
Days left: 32
These figures are not off. A quick check would be: time difference in millis was: 2812500000 => in seconds would be diff/1000 = 2812500 => in minutes would be => diff/1000/60 = 46875 and so on.
Relative time:
To get relative time such as 32 days, 13 hours and 15 minutes left, you will have to do the heavy-lifting yourself. As an example:
// I will use the actual values instead of defined
// variables to make this easier to follow
long timeDiff = 2812500000L;
// Simple division // we don't care about the remainder
// Result: 32
int days = 2812500000 / DateUtils.DAY_IN_MILLIS;
// This is what's left over after we take the days out.
// We'll use this to get the number of hours.
// Result: 47700000
long remainderFromDays = 2812500000 % DateUtils.DAY_IN_MILLIS;
// Simple division // we don't care about the remainder
// Result: 13
int hours = 47700000 / DateUtils.HOUR_IN_MILLIS;
// This is what's left over after we take the hours out.
// We'll use this to get the number of minutes.
// Result: 900000
long remainderFromHours = 47700000 % DateUtils.HOUR_IN_MILLIS;
// Result: 15
int minutes = 900000 / DateUtils.MINUTE_IN_MILLIS;
// Result: 0
long remainderFromMinutes = 900000 % DateUtils.MINUTE_IN_MILLIS;
// Result: 0
int seconds = 0 / 1000; // 1000 ms = 1 sec
Log.i("Time-Difference", "Event in: " + String.format("Event in %d days, %d hours, %d minutes and %d seconds", days, hours, minutes, seconds));
Output:
Event in: 32 days, 13 hours, 15 minutes and 0 seconds
This is the very reason everyone here is suggesting Joda Time. The computation above is just off the top of my head. I cannot guarantee its correctness. If you also need relative month difference (such as 3 months, 2 days ....), a lot of work will be required. There isn't a DateUtils.MONTH_IN_MILLIS constant - varying number of days - 28, 29, 30, 31.
On the other hand, Joda Time is a tried & tested product. But, if all you need is one kind of computation, used scarcely (if ever), I'd say spend some time and come up with your own implementation rather than under-employ Joda Time.

Your code looks fine to me for what you are doing. Using org.joda.time as others have suggested is a best-practice, but it won't fix the problem. Instead you need to do two things:
Verify the Month that the user entered is in range (they may have entered the date in MM/DD/YYYY format). Month values greater than 12 won't throw an exception and your diff will be way off.
The line where you construct your date, subtract 1 from the month since months should be from 0 to 11, like:
newCalendar.set(yearE, monthE-1, dayE,hour, min, 0);

Change DateFormat depending on Days passsed

Essentially what I have is a string which contains a files Last Modified Date. To get this I'm using:
Date lastModDate = new Date(file.lastModified());
SimpleDateFormat formatter = new SimpleDateFormat("K:mm a");
String formattedDateString = formatter.format(lastModDate);
The end result is somewhat like 6:12 AM. What I want to do is each time a certain period of time is passed, the dateformat must change. E.g.
After 1 Day has gone by, Last Modified Date = ("Format1");
After a Week has gone by, Last Modified Date = ("Format2");
After 2 Weeks have gone by, Last Modified Date = ("Format3");
Does it make sense? If so is someone please be able to show me how it's done. A good example is the native Messaging App. When a message is created, It will show it's Time then after some days gone by the format changes to the Date it was created then the month etc...
I'm trying to do exactly that.

Calculate the difference in time between the last modified date and now:
long duration = lastModDate.getTimeInMillis() - current.getTimeInMillis();
long sec = TimeUnit.MILLISECONDS.toSeconds(duration);
boolean inFuture = sec > 0;
// Use positive value
if(!inFuture)
sec = -sec;
long minutes = sec / 60 % 60;
long hours = sec / 3600 % 24;
long days = sec / 86400;
if(days > 1 && days < 7)
// Use format 1
else if(days >= 7 && days < 14)
// Use format 2
else
// Use format 3

How to get the Time like facebook post eg. 1sec ago or 3hrs ago, In android application

I have developed an application where the user receives the message from other application user. I want to just show the time like Facebook, eg. 1sec ago or 3Hrs ago. Something in this fashion. I tried a code from one of our Fellow S.O expert but that code seems to misbehave.
Here's the code which i used in my app.
static SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
static int[] steps = { 1, 60, 3600, 3600 * 24 };
static String[] names = { "sec", "mins", "hrs", "days" };
public static String formatDelay(String date) {
try {
Date d = sdf.parse(date);
Long stamp = d.getTime();
Calendar c = Calendar.getInstance();
Long now = System.currentTimeMillis() / 1000;
Format format = new SimpleDateFormat("yyyy MM dd HH:mm:ss");
String time = format.format(now);
Long dif = now - stamp;
dif = dif / 1000;
if (stamp > now)
return "";
for (int i = 0; i < steps.length; i++) {
if (dif < steps[i]) {
String output = Long.toString(dif / steps[i - 1]) + " "
+ names[i - 1];
return output;
}
}
return Long.toString(dif / steps[3]) + " " + names[3];
} catch (Exception e) {
e.printStackTrace();
return "";
}
}
When I used this code and sent a message from my application , it should show me sent 1sec ago, but in my case it shows me wrong time delay. For eg. I sent the message at 6pm then when I check my application sent item at 6:15pm its should show me 15 mins ago. But it shows me 12 hrs. When i debugged code, got to know that now time show date as 1970 00:00:00, this is because Long now = System.currentTimeMillis() / 1000; when i remove that /1000 it shows me correct date and time. I am clue less why this is happening please help.

Use
android.text.format.DateUtils.getRelativeTimeSpanString (long time, long now, long minResolution, int flags)
this will return time span in String format
For eg. if you pass a long value corresponding to 42 minutes ago in time and flags as DateUtils.FORMAT_ABBREV_RELATIVE the method will return 42 minutes ago
Official documentation DateUtils.getRelativeTimeSpanString

When you divide System.currentTimeMillis() by 1000 you are converting its value to seconds.
You're then using that value to create a date which is interpreting the seconds value as the milliseconds since Thu Jan 01 1970, hence the date difference.

I would recommend using Joda-Time API. See this answer for reference.

Subtract two datepickers in android [duplicate]

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How do I calculate someone's age in Java?
(28 answers)
Closed 8 years ago.
Is there any way to subtract two dates from picker.
Example:
I will select a date from picker1 and date from picker2.
Then, picker2 - picker1 to get the number of days between these two dates.
20/10/2014
(-) 06/10/2014
--------------
14 days

DateTimeUtils obj = new DateTimeUtils();
SimpleDateFormat simpleDateFormat =
new SimpleDateFormat("dd/M/yyyy hh:mm:ss");
try {
Date date1 = simpleDateFormat.parse("10/10/2013 11:30:10");
Date date2 = simpleDateFormat.parse("13/10/2013 20:35:55");
obj.printDifference(date1, date2);
} catch (ParseException e) {
e.printStackTrace();
}
}
//1 minute = 60 seconds
//1 hour = 60 x 60 = 3600
//1 day = 3600 x 24 = 86400
public void printDifference(Date startDate, Date endDate){
//milliseconds
long different = endDate.getTime() - startDate.getTime();
System.out.println("startDate : " + startDate);
System.out.println("endDate : "+ endDate);
System.out.println("different : " + different);
long secondsInMilli = 1000;
long minutesInMilli = secondsInMilli * 60;
long hoursInMilli = minutesInMilli * 60;
long daysInMilli = hoursInMilli * 24;
long elapsedDays = different / daysInMilli;
different = different % daysInMilli;
long elapsedHours = different / hoursInMilli;
different = different % hoursInMilli;
long elapsedMinutes = different / minutesInMilli;
different = different % minutesInMilli;
long elapsedSeconds = different / secondsInMilli;
System.out.printf(
"%d days, %d hours, %d minutes, %d seconds%n",
elapsedDays,
elapsedHours, elapsedMinutes, elapsedSeconds);
}
output is this
startDate : Thu Oct 10 11:30:10 SGT 2013
endDate : Sun Oct 13 20:35:55 SGT 2013
different : 291945000
3 days, 9 hours, 5 minutes, 45 seconds
Answer from this link Android difference between Two Dates

Since not much information is provided, I assume you are using DatePicker
The basic flow is like that:
by calling getDayOfMonth(), getMonth() and getYear() from DataPicker to obtain day, month and year respectively.
after obtaining those information, I think you should be able to calculate the day difference between them.
Just for your reference, the following is a topic about day difference, hope this help.
Difference in days between two dates in Java?

short and simple
SimpleDateFormat simpleDateFormat= new SimpleDateFormat("dd/MM/yyyy");
java.util.Date date1 = null;
java.util.Date date2 = null;
try {
date1 = simpleDateFormat.parse("20/10/2014");
date2 = simpleDateFormat.parse("06/10/2014");
} catch (java.text.ParseException e) {
e.printStackTrace();
}
int diffInDays = (int) ((date1.getTime() - date2.getTime())/ (1000 * 60 * 60 * 24));
EDIT :
Hello Uday
it is Very Simple you have two EditText so first Set your date into et and et1 and now
et.getText().toString(); //Do same for et1 also
this mothod will helps you for getting date and now apply to my code

Counting dates on Android

Well i'm currently building an app for android and i need to store a day and count how many days until that day comes.
I store the day on shared prefs. First i initialize the calendars.
Calendar next = Calendar.getInstance();
Calendar now = Calendar.getInstance();
Then i set the "next" calendar
nday = prefs.getInt("d", 0);
nmonth = prefs.getInt("m",0);
nyear = prefs.getInt("y",0);
next.set(nyear, nmonth, nday);
Then i do this to calculate how many days left.
diff =next.getTimeInMillis()-now.getTimeInMillis();
diffDays = diff / (24 * 60 * 60 * 1000);
output.setText(diffDays + " Days left");
And here is the problem. The calculator was working great until 2 days ago. When it supposed to say "3 days" it was writing "2 days" and it still goes one day wrong. If i try close and open the app, sometimes it calculates the days correct and sometimes it misses one day... Can someone understands whats wrong? I have diff and diffDays as long. I tried cast them as int but i still got the same problem, sometimes it writes 3 days left, sometimes 2....
ok i found out how to solve this. It seems that the getInstance have difference in milliseconds so i did this
Calendar now = Calendar.getInstance();
now.set(Calendar.HOUR_OF_DAY,00);
now.set(Calendar.MINUTE ,00);
now.set(Calendar.SECOND,00);
now.set(Calendar.MILLISECOND,00);
get the day from shared prefs
nday = extras.getInt("nDay");
nmonth = extras.getInt("nMonth");
nyear = extras.getInt("nYear");
//set the calendar
next.set(nyear, nmonth, nday, 00, 00,00);
next.set(Calendar.MILLISECOND,00);
and finally calculate the difference
long diff = 0;
diff = next.getTimeInMillis()-now.getTimeInMillis();
diffDays = diff / (24 * 60 * 60 * 1000);
output.setText(diffDays + " Days");
now i get the real difference without any mistakes, thanks everyone for your help!

Because it is implicitly casting to long, so you are losing some of your minutes and hours.
Declare diffDays as double, then you can show to the user when there are, for example 2.5 days and it won't show it as 2 days. Or, you could take the integer part for the days, and calculate the hour from the fraction:
int hour = (diffDays - Math.floor(diffDays))*24
This gives you the minute. Just make sure you did declare diffDays as double or float.

Also use the calendar for calculating dates.
Calendar diff = Calendar.getInstance();
long diffMillis = next.getTimeInMillis()-now.getTimeInMillis();
diff.setTimeInMilliSeconds(Math.abs(diffMillis));
int days = diff.get(Calendar.DAY_OF_YEAR);
if (diffMillis < 0L) {
days *= -1;
}