[
https://issues.apache.org/jira/browse/LANG-312?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12462850
]
Dennis Lundberg commented on LANG-312:
--------------------------------------
I'm in GMT+1 with locale sv_SE.
> DateFormatUtils.format with Timezone parameter "CET" produces wrong date in
> summer time 1945 to 1949
> ----------------------------------------------------------------------------------------------------
>
> Key: LANG-312
> URL: https://issues.apache.org/jira/browse/LANG-312
> Project: Commons Lang
> Issue Type: Improvement
> Affects Versions: 2.1, 2.2
> Environment: IBM Java 1.4.2, Sun Java 1.4.2, Windows XP, SuSE Linux
> Enterprise 9, German systems, at winter time
> Reporter: Hayo
> Fix For: 3.0
>
>
> DateFormatUtils.format(dt, "dd/MM/yyyy", Timezone.getTimezone("CET"),
> Locale.GERMANY); returns the date of the day before during summer time of the
> years 1945 to 1949. The problem was detected on a system running in
> Locale.GERMANY, current time "CET", JDK 1.4.2.
> The problem does not occur with the call DateFormatUtils.format(dt,
> "dd/MM/yyyy"); which presumably uses the system defaults. These are likely to
> be the same as the parameters i have passed.
> The following code snippet demonstrates the problem:
> for (int year = 0; year < 150; year ++) {
> for (int month = 0; month <= 11; month ++) {
> for (int day = 1; day <= 28; day ++) {
> java.sql.Date dt = new java.sql.Date(year, month, day);
> // or java.util.Date
> String def = DateFormatUtils.format(dt, "dd/MM/yyyy");
> String cet = DateFormatUtils.format(dt, "dd/MM/yyyy",
> Timezone.getTimezone("CET"), Locale.GERMANY);
>
> if (!cet.equals(def)) {
> System.err.println(dt.toLocaleString() + " Default: "
> + def + " CET: " + cet);
> }
> }
> }
> }
>
> Output:
> ------
>
> 03.04.1945 00:00:00 Default: 03/04/1945 CET:02/04/1945
> [...]
> 18.11.1945 00:00:00 Default: 18/11/1945 CET:17/11/1945
> 15.04.1946 00:00:00 Default: 15/04/1946 CET:14/04/1946
> [...]
> 07.10.1946 00:00:00 Default: 07/10/1946 CET:06/10/1946
> 07.04.1947 00:00:00 Default: 07/04/1947 CET:06/04/1947
> [...]
> 05.10.1947 00:00:00 Default: 05/10/1947 CET:04/10/1947
> 19.04.1948 00:00:00 Default: 19/04/1948 CET:18/04/1948
> [...]
> 03.10.1948 00:00:00 Default: 03/10/1948 CET:02/10/1948
> 11.04.1949 00:00:00 Default: 11/04/1949 CET:10/04/1949
> [...]
> 02.10.1949 00:00:00 Default: 02/10/1949 CET:01/10/1949
> This seems to be during the summer time of 1949 to 1945 in Berlin, and only
> in Berlin. Setting the Locale to any other value has no effect on that. So i
> ask myself, what results other central european users get. Setting the
> Timezone to "GMT+2" extracts exactly the high summer times in 1945 and 1947
> (MEHSZ). (See below for list of summer times).
> I could guess that some calendar calculations work with different libraries
> that have different summer time maps (java.util.Date vs. Calendar). This
> might depend on my environment, so this task should be tested by others (with
> their local Timezone).
> The API documentation does not clearly state what effect the Timezone/Locale
> parameters should have.
> In my strong opinion at least dates passed as java.sql.Date should not be
> normalized to summer/standard time. A date is a date! For java.util.Date the
> date recalculation behaviour should be mentioned in the docs, if it is really
> intended this way by design.
> ===============================================================================
> These where the actual summer times in Germany
> (http://www.ptb.de/de/org/4/44/441/salt.htm
>
> http://de.wikipedia.org/wiki/Hochsommerzeit#Mitteleurop.C3.A4ische_Sommerzeit)
> a) Summer time, Advance to CET (GMT+1): 1 hour (GMT+2)
> 1916-04-30 23:00:00 CET until 1916-10-01 1:00:00 CEST
> 1917-04-16 2:00:00 CET until 1917-09-17 3:00:00 CEST
> 1918-04-15 2:00:00 CET until 1918-09-16 3:00:00 CEST
> 1919 until 1939: No Summer time
> 1940-04-01 2:00:00 CET until 1942-11-02 3:00:00 CEST
> 1943-03-29 2:00:00 CET until 1943-10-04 3:00:00 CEST
> 1944-04-03 2:00:00 CET until 1944-10-02 3:00:00 CEST
> 1945-04-02 2:00:00 CET until 1945-09-16 2:00:00 CEST
> Special: Berlin and sowjet occupied zone:
> (1945-05-24) 2:00:00 CET until 1945-11-18 3:00:00 CEST
> (1945-05-24) 3:00:00 CET until 1945-09-24 2:00:00 MEHSZ
> 1946-04-14 2:00:00 CET until 1946-10-07 3:00:00 CEST
> 1947-04-06 3:00:00 CET until 1947-10-05 3:00:00 CEST
> 1948-04-18 2:00:00 CET until 1948-10-03 3:00:00 CEST
> 1949-04-10 2:00:00 CET until 1949-10-02 3:00:00 CEST
> b) High summer time, Advance to CET: 2 hours (GMT+3)
> 1947-05-11 3:00:00 CEST until 1947-06-29 3:00:00 MEHSZ
> c) From 1950 to 1979 no Summer times
> d) 1980 to now (most of central europe)
> 1980-04-06 2:00:00 CET until 1980-09-28 3:00:00 CEST
> ...
> ongoing until today
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
https://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
