topic Re: ConvertToLocalTime: Change in QV11 to QV12 in Archived Groups

ConvertToLocalTime: Change in QV11 to QV12

rwunderlich — Wed, 23 Jul 2025 14:48:52 GMT

In the ConvertToLocalTime() function, there is a difference in DST (daylight savings) handling between QV10/11/12 and QV12.10.

QV11 applied DST processing to City placenames as well as placenames of the form "GMT-nn". QV12.10 does not apply DST when "GMT-nn" or "UTC-nn" is used. It can't be forced with the ignore_dst parameter either. I can't find anything in the doc or release notes on this change.

-Rob

Re: ConvertToLocalTime: Change in QV11 to QV12

rbecher — Fri, 03 Nov 2017 14:12:46 GMT

Actually, I think this is wrong for the US only but not for the whole timezone GMT-05:00 !

Re: ConvertToLocalTime: Change in QV11 to QV12

rwunderlich — Fri, 03 Nov 2017 14:16:56 GMT

Ralf,

I think it's wrong for the US today because we are still on DST (we go off Sunday). If you test this in Europe, it will appear correct because you are already off DST.

It will be "correct" for all of us on Monday morning

-Rob

Re: ConvertToLocalTime: Change in QV11 to QV12

rbecher — Fri, 03 Nov 2017 14:22:12 GMT

I know because of Halloween. I meant there are more countries in that timezone than the US and US just breaks the rule here. So this is not THE US timezone.

I think at least Jamaica is in same timezone but w/o DST now.

Re: ConvertToLocalTime: Change in QV11 to QV12

rbecher — Fri, 03 Nov 2017 14:26:15 GMT

So to me it's right than GMT-05:00 is just not specific enough..

Re: ConvertToLocalTime: Change in QV11 to QV12

rwunderlich — Fri, 03 Nov 2017 14:48:19 GMT

I understand what you are saying Ralf. All locations in DST-nnnn are not observing DST for the same dates, if observing it at all. So the QV12 behavior is correct, QV11 was wrong in some cases.

So the doc should be updated to reflect that GMT-nnnn names do not consider DST.

-Rob