Warren,
First I am a bit confused about this. You said your photos were all taken with the camera set to the correct time and time zone when taken, and your computer at the correct time zone when you did your daily ingest with your laptop. So why is it that you need to adjust the capture times?
Second, much of PM's ability to handle time zone correctly relies upon PM being able to read the time zone info that is stored in the proprietary Exif maker note section of the raw or jpeg file. There is no Exif standard for time zone (as a TIFF-based tag). PM can read the maker note time zone info (including daylight savings flag) for recent Nikon and Canon cameras that are capable of writing this info. But not for Sony (their maker note is very dependent on the exact model and therefore requires a lot of work). Also, PM will not update the Nikon or Canon proprietary time zone data in the maker note (although I suspect the ExifTool can do this).
What I would like to have is a sample photo from the Sony camera before and after PM makes the time adjustment. I'd also like to see an explanation of what the time zone is supposed to be and what the adjustment is that you are trying to make in the adjust capture times dialog, and the expected result. As I mentioned, until there is an Exif standard for time zone, the adjust capture times tool cannot make this change, and even if it did you may still need to change the time (e.g. maybe someone changes the time in the camera instead of the time zone by accident when they travel and therefore they would potentially need to change both depending on whether or not changing the time zone would also change the time - typically these settings are made independently).
Hayo: you said you can reproduce this. Is this from a Nikon photo? And how did you reproduce?
I will take a quick look at the adjust capture times logic, but the best way for me to fix this (if possible given that we don't read Sony time zone info from their maker note) is to have a sample file and a way to reproduce the issue.
BTW regarding your previous posts about time zone:
1) As I think Kirk explained, the XMP spec doesn't say anything about how Adobe or anyone else should format their data. That is the whole point of XMP (extensible metadata). Adobe chose to use ISO 8601 for their photoshop:DateCreated field in XMP - a logical choice. Kirk explained that the 8601 spec is very flexible and can be as simple as a year YYYY without a month, day, or time. So not including a time zone is not a "going against the XMP standards" as you claim. Try opening a photo into Photoshop (even the latest CC version), then make some adjustment, then do a save-as. Do you see the time zone in Photoshop's own photoshop:DateCreated tag in the XMP of the Photoshop-saved file? I don't. I don't see either the correct time zone (+2 from Munich) or my local time zone (-8 for Oregon), but I do see the sub seconds (which if you argue that time zone is a requirement then you should argue that the sub seconds is also a requirement, but I disagree with the need to include either and apparently you forcefully remove the sub seconds). So I would say that since this is Adobe Photoshop's own namespace and field (NOT an XMP "standard") and Photoshop itself doesn't write the time zone, even the local time zone, then perhaps that was Adobe's intention to not include this? Maybe they agree with Hayo that if you don't know what the time zone is then it shouldn't be written (because to write the field means you are asserting that this is indeed the correct time zone). Adobe probably decided not to bother with reading proprietary maker note data to retrieve the time zone (especially since this is a legal gray area regarding DMCA), but since the Exif standard DOES include a capture time sub seconds, then Adobe writes this out with their XMP photoshop:DateCreated field. We made a similar change at Hayo's request to not write time zone if it isn't known, which you didn't like, and so for you we created the special PMDebug.txt flag to FORCE the local time zone to be written if we can't determine the time zone from the camera. We used to default to local time zone and always write it out (although there was a bug introduced at some point causing the delta hours to be put into delta minutes).
2) The old IPTC-IIM specification REQUIRES that a time zone be written. This is a very rigid specification. The time tag must be exactly formatted to include +HHMM or -HHMM. So PM has to put SOME value there, and the most logical choice (for a camera make that PM doesn't read the time zone like Sony) is to use the local computer's time zone. The other choice would be to put 0000 but that can't be separated from a legitimate photo taken at GMT time zone.
3) Do you have some utility that automatically determines your geolocation based solely on date/time and time zone (and maybe City/Country)? How accurate can that possibly be? I thought you would point at a map or load a log file from a GPS tracking device and use our utility Import GPS Coordinates (which will ask you what the GMT offset is).
Please forward sample Sony JPEGs with the info I requested above and I'll delve into this further to see what we can do. You can send this to me as a private message if you would like (but you'll need to provide a link to download your sample since the personal messages system does not allow sending of files.)
Regards,
--dennis