[PIG-3864] ToDate(userstring, format, timezone) computes DateTime with strange handling of Daylight Saving Time with location based timezones

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.12.0, 0.11.1
• Fix Version/s: 0.18.0
• Hadoop Flags: Reviewed
• Assignee: Daniel Dai
• Reporter: Frederic Schmaljohann
• Created: 03/Apr/14 13:41
• Updated: 27/Dec/17 19:11
• Resolved: 27/Dec/17 19:11

Description

When using ToDate with a location based timezone (e.g. "Europe/Berlin") the handling of the timezone offset is based on whether the timezone is currently in daylight saving and not based on whether the timestamp is in daylight saving time or not.

Example:

B = FOREACH A GENERATE ToDate('2014-02-02 18:00:00.000Z', 'yyyy-MM-dd HH:mm:ss.SSSZ', 'Europe/Berlin') AS Timestamp;

This yields

2014-02-02 20:00:00.000+02

when called during daylight saving in Europe/Berlin although I would expect

2014-02-02 19:00:00.000+01

During standard time In Europe/Berlin, the above call yields

2014-02-02 19:00:00.000+01

In Europe/Berlin DST started on March 30th, 2014.

This seems pretty strange to me. If it is on purpose it should at least be noted in the documentation.