CODEWITHSUNDEEP
androiddatedatetimecalendartimezone
Sandip Armal Patil
Sandip Armal Patil

Reputation: 5905

Android Calendar.getTime().getTime() always returning -1 day

I creating calendar instance by providing timezone and then setting day, month and year to calendar. But when I am trying to gettime in millisecond then it always returning dateTime in millisecond -1 day.

Here is How I am setting Calendar.

DatePickerDialog datePickerDialog = new DatePickerDialog(Objects.requireNonNull(getContext()), R.style.DialogTheme, (view, year, month, dayOfMonth) -> {
        Calendar calendar = new DateUtils().getCountryCalendar();
        calendar.set(Calendar.YEAR, year);
        calendar.set(Calendar.MONTH, (month));
        calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        calendar.set(Calendar.MILLISECOND, 0);
        long selectedDate = calendar.getTime().getTime();
    }, mYear, mMonth, mDay);

I am setting bu it returning me selectedDate as 1624986000000 which is Tue Jun 29 2021 22:30:00

Here is getCountryCalendar() method.

If I am selecting 30th June then it should return 30th June in millisecond. I don't know why it's happening. Any suggestion are appreciated.

public Calendar getCountryCalendar() {

    return Calendar.getInstance(TimeZone.getTimeZone("Asia/Bangkok"));
}

Upvotes: 0

Views: 552

Answers (2)

Basil Bourque
Basil Bourque

Reputation: 339043

tl;dr

LocalDate
.of( y , m , d )
.atStartOfDay( ZoneId.of( "Asia/Bangkok" ) )
.toInstant()
.toEpochMilli()

java.time

The modern solution uses the java.time classes that years ago supplanted the legacy date-time classes such as Calendar.

Build your date-only value.

LocalDate ld = LocalDate.of( y , m , d ) ;

Apparently you want the first moment of the day in that date as seen in a particular time zone. Do not hard-code a time of 00:00:00.0. That time of day may not exist on some dates in some time zones. Let java.time determine the first moment of the day.

ZoneId z = ZoneId.of( "Asia/Bangkok" ) ;
ZonedDateTime zdt = ld.atStartOfDay( z ) ;

Apparently you want to convert that to a count of milliseconds from the epoch reference of first moment of 1970 as seen in UTC. The Instant class represents a moment as seen in UTC.

long millis = zdt.toInstant().toEpochMilli() ;

Upvotes: 2

SadClown
SadClown

Reputation: 658

The timestamp 1624986000000 indeed is Jun 30, 00:00:00 by Asia/Bangkok time zone. You can even check it here.

On the other side, Colcata and Colombo timezones render this timestamp as Jun 29 2021 22:30:00.

Since you haven't shared the code where you convert timestamp to 22:30:00, my assumption that in that piece of code you are not using the right timezone (but rather Asia/Colcata, or Asia/Colombo, or something else that matches GMT +05:30)

Upvotes: 1

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