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https://issues.apache.org/jira/browse/DERBY-7091?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17236964#comment-17236964
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Richard N. Hillegas commented on DERBY-7091:
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Parsing and formatting of timestamps is handled by classes in the JDK. I can
think of only one knob which might affect this behavior. You can try changing
the timezone of the JVM as described here:
https://docs.oracle.com/javase/9/troubleshoot/time-zone-settings-jre.htm#JSTGD377
But I don't think that will help.
I think that the problems you are seeing are baked into the old time-handling
classes in the JDK. See, for instance,
https://stackoverflow.com/questions/45463059/behaviour-of-gregoriancalendar-set-with-daylight-saving-times
The defects in those classes were the reason that Java 8 introduced the
java.time package.
The fix would be to implement a TIMESTAMP WITH TIME ZONE data type, backed by
the classes in java.time.
> Times Inserted Incorrectly Around Daylight Savings Time Change in Spring
> ------------------------------------------------------------------------
>
> Key: DERBY-7091
> URL: https://issues.apache.org/jira/browse/DERBY-7091
> Project: Derby
> Issue Type: Bug
> Affects Versions: 10.14.2.0
> Environment: Java 14.0.1
> Reporter: Larry Melvin Lemons
> Priority: Critical
> Attachments: Test.java, Timezone_Data_Inconsistencies.odt
>
>
> When inserting date/times into the timestamp field around the daylight
> savings time change in the Spring, the times are inconsistent. I am in/use
> the New York EST/EDT timezone, but the data I am inserting is Standard time
> and not Daylight Savings Time
> All the times are correct up to 1:48AM, then when it inserts 2:00 AM the data
> in the database is 3:00AM. That could be alright if it kept switching the
> time to Daylight Savings Time, however going from inserting 2:48AM and
> getting 3:48AM in the database, when it inserts 3:00AM it shows 3:00AM in the
> database, not the expected 4:00AM. Then in the fall whatever is inserted in
> the database is what shows in the database around the daylight savings time
> switch to standard time. See the attached Open Document Text file for
> examples of what is actually inserted and what is showing in the database.
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