Not getting expected daylight savings transition times.

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Not getting expected daylight savings transition times.

java.peritus@gmail.com

Given the following code using a US/Eastern timzone:

        final DateTimeFormatter format = DateTimeFormat.mediumDateTime();
        final DateTimeZone tz = DateTimeZone.forID("US/Eastern");
        final long currentDateInMillis = System.currentTimeMillis();

        final DateTime firstTransition = new
DateTime(tz.nextTransition(currentDateInMillis), tz);
        final DateTime secondTransition = new
DateTime(tz.previousTransition(currentDateInMillis), tz);

        System.out.println("First Transition: " +
format.print(firstTransition));
        System.out.println("Second Transition: " +
format.print(secondTransition));


Can someone explain to me why I get the following for output:

        First Transition: Nov 6, 2011 1:00:00 AM
        Second Transition: Mar 13, 2011 1:59:59 AM


The transitions for US/Eastern timezones occur at 2 AM so why am I
seeing 1:00 AM and 1:59:59 AM?


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Re: Not getting expected daylight savings transition times.

jodastephen
The next transition is in Autumn/Fall when clocks go back. I presume
that the hour 01:00 to 02:00 is repeated in your area.

The nextTransition() method returns the time just after the
transition. 02:00 (summer) never happens, so the method returns 01:00
(winter).

The previousTransition() method returns the last millisecond before
the transition. Remember that in Spring, 02:00 never happens during
the DST gap, so the method cannot return 02:00.

To print the transition time, use previousTransition(), convert it to
a LocalDateTime, then add one millisecond.

Stephen


On 1 June 2011 15:13, [hidden email] <[hidden email]> wrote:

>
> Given the following code using a US/Eastern timzone:
>
>        final DateTimeFormatter format = DateTimeFormat.mediumDateTime();
>        final DateTimeZone tz = DateTimeZone.forID("US/Eastern");
>        final long currentDateInMillis = System.currentTimeMillis();
>
>        final DateTime firstTransition = new
> DateTime(tz.nextTransition(currentDateInMillis), tz);
>        final DateTime secondTransition = new
> DateTime(tz.previousTransition(currentDateInMillis), tz);
>
>        System.out.println("First Transition: " +
> format.print(firstTransition));
>        System.out.println("Second Transition: " +
> format.print(secondTransition));
>
>
> Can someone explain to me why I get the following for output:
>
>        First Transition: Nov 6, 2011 1:00:00 AM
>        Second Transition: Mar 13, 2011 1:59:59 AM
>
>
> The transitions for US/Eastern timezones occur at 2 AM so why am I
> seeing 1:00 AM and 1:59:59 AM?
>
>
> ------------------------------------------------------------------------------
> Simplify data backup and recovery for your virtual environment with vRanger.
> Installation's a snap, and flexible recovery options mean your data is safe,
> secure and there when you need it. Data protection magic?
> Nope - It's vRanger. Get your free trial download today.
> http://p.sf.net/sfu/quest-sfdev2dev
> _______________________________________________
> Joda-interest mailing list
> [hidden email]
> https://lists.sourceforge.net/lists/listinfo/joda-interest
>

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