I think I've found the answer. Due to an amazingly silly feature of
the TimeZone API which returns a GMT timezone for invalid timezone ids
(not null or exception as you'd expect) ... i didn't notice that the
correct timezone id should have been "GB-Eire" and not "GB/Eire".
Sorry...
Joe.
On 4/17/07, Joe Desbonnet <joe@xxxxxxxxxx> wrote:
Just when I thought I really understood the Java time API this test
case below threw me today. Same results with the current FC6 Java
stack (up to date) and Sun JDK (1.5.0_07).
Why oh why is 17:00 UK/Irish local time the same as 17:00 UTC ? The
local time should be one hour ahead due to daylight savings.? Funny -
I wrote lots of code last year relating to logging sensor data and I
had no problems normalizing the timestamps to UTC. Now I just can seem
to do it. A bug in Java timezone files or my brain?
import java.util.Date;
import java.util.TimeZone;
import java.text.SimpleDateFormat;
public class DateTest {
public static void main (String arg[]) throws Exception {
TimeZone localTz = TimeZone.getTimeZone ("GB/Eire");
SimpleDateFormat localDateFormat = new SimpleDateFormat ("yyyyMMdd HH:mm:ss");
localDateFormat.setTimeZone(localTz);
TimeZone utcTz = TimeZone.getTimeZone ("UTC");
SimpleDateFormat utcDateFormat = new SimpleDateFormat("yyyyMMdd HH:mm:ss");
utcDateFormat.setTimeZone(utcTz);
String datetime = "20070417 17:00:00";
Date d1 = localDateFormat.parse(datetime);
Date d2 = utcDateFormat.parse(datetime);
if (d1.getTime() == d2.getTime()) {
System.err.println ("Error: GB/Eire = UTC + Daylight Savings (ie
d1-d2 = 1 hour, not 0 hour)");
}
}
}
--
fedora-devel-java-list mailing list
fedora-devel-java-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/fedora-devel-java-list
