This has been raised many times over the recent years.
When importing from non-apple device such as Olympus M10, all time stamps are wrong in Photos. Looks as they're simply not considering time zone. As there is no time zone marking in the native camera, Photos should interpret it as to the time zone set on the Apple device.
Any more info on this from the Community?
Images:
macOS 13-14 Ventura-Sonoma (I have not yet tested this in Sequoia) Photos.app prioritizes sorting imported images like .jpg in the same manner as movies although the metadata tags are different.
1. Image's internal metadata 'ExifIFD:DateTimeOriginal' sets the date and time. If it is not present, there are numerous other internal metadata tags that might set the time. If none of those internal metadata dates exist, then as a last resort Photos grabs the date from macOS file system 'MacOS:FileCreateDate' (social media sites like Facebook, WhatsApp etc strip internal metadata from images and movies). Modifying an image usually changes macOS file system 'System:FileModifyDate' but Photos ignores that date when importing anyway.
In both cases image's time zone is set using the computer's time zone location (standard time New York EST -05:00, Berlin +01:00, for example) when the image is imported to Photos library. DST for that date is also automatically set (daylight saving time New York EDT -04:00, Berlin +02:00, for example).
Also macOS file system 'MacOS:FileCreateDate' time changes depending on the computer's time zone location in a similar manner. File system time stamps are similar to the QuickTime time stamps: they are basically UTC, but the computer automatically shows you the time adjusted to the computer's local time zone. It is best to set the date to the internal metadata dates because file dates are fragile.
Changing the computer to another time zone preserves the time and time zone in the previously imported images.
If present, the following internal metadata tags override previously mentioned time zone, and they might affect sorting up to ±12 hours if they happen to be present in some image:
2. 'GPS' location sets the time zone. Notice that the time zone might be different in the same longitude depending on the latitude. For example, Dhaka in Bangladesh is +06:00 while the same longitude in China is +08:00.
3. If 'ExifIFD:OffsetTimeOriginal' exists, it overrides all other time zone tags above. BTW some iOS ~13.2.2 and later devices do not have GPSTimeStamp anymore, only GPSDateStamp, and the GPSTimeStamp offset is moved to 'OffsetTime*' tags. Photos ignores the similar 'OffsetTime' and 'OffsetTimeDigitized' tags that are often also present.
'ExifIFD:DateTimeOriginal' and GPS can be checked in macOS Finder > Show Preview > Show More > 'Content Created' date in the right side panel. Or in Preview.app > Tools > Show Inspector > i > Exif > 'Date Time Original' field which shows also the possible Time Zone info -- GPS info is also in that dialog.
More info and movie details at:
Movie dates and Photos.app - Apple Community
Historically, Photos has indeed used the time zone on your Mac at the time you import photos there. People have gotten into trouble by waiting until they got home (or until their next stop) to do the import.
I'm not sure how Photos has handled the matter if you do the import using iOS or iPadOS. I also haven't imported any non-Apple photos to my Macs in a few months, so even there it might have changed.
Apple Photos still ignoring time zone when importing
