CODEWITHSUNDEEP
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Mdjon26
Mdjon26

Reputation: 2255

Converting to Eastern Time Zone (North America)

I have this piece of code for a client in Eastern time zone:

public DateTime getActivityDate() {
    return new DateTime(activityDate, DateTimeZone.UTC).minusHours(5);
}

The client was reporting it was working until the time change back in November. Now they are reporting they are seeing the times as " 1 hour ahead of Eastern time zone."

Is there any way I can get this working for both davelight savings time and standard time instead of hardcoding it as minusHours(5) and minusHours(6)?

Upvotes: 1

Views: 727

Answers (2)

Meno Hochschild
Meno Hochschild

Reputation: 44061

Yes, please use the appropriate timezone identifier for New York - time:

return new DateTime(activityDate, DateTimeZone.forID("America/New_York"));

By the way: It is a wrong idea to do time arithmetic like minusHours(5) here in order to take tz offsets into account. What you are doing, is also changing the instant/moment given by activityDate and not just changing the local representation in appropriate timezone. Example showing the difference between your code and my proposal:

System.out.println(new DateTime(new Date(), DateTimeZone.forID("America/New_York"))); 
// 2016-12-19T11:05:58.507-05:00

System.out.println(new DateTime(new Date(), DateTimeZone.UTC).minusHours(5)); 
// 2016-12-19T11:05:58.573Z

We have same "local" representations but different offsets (-05 versus Z=+00) resulting in different instants. Only my proposal yields correct local time (for New York) AND correct instant.

Upvotes: 3

TheBakker
TheBakker

Reputation: 3042

If you are using org.joda.time.DateTime :

public static final DateTime getEasternUSLocalDateTime(DateTime pDateTimeUtc) {

    // Convert the Date
    DateTime convertedDate  = originalDate.withZone(DateTimeZone.forID("America/New_York"));
    // Return the localTime associated with the timeZone
    return convertedDate.toLocalDateTime();
}

Upvotes: 1

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