Time Zone control in Photos App

I'm trying to get the times, dates and time zones corrected on certain images in the Photos app. It seems it only allows time and date correction though, not time zone. Does Photos disregard time zone altogether? I just don't want to change the time and date of photos if all I'm doing is changing it to an incorrect time and date because time zone isn't being included.

For example: If the photo is set to to EST and the metastamp says it was taken at 3 pm, but the photo was taken in California, you'd think to change the time to 12 pm. However, if the time zone doesn't change, you are really changing the time to 9 am PST (not 12 pm) because it is still being counted in EST.

Basically, time and date are dependent on the time zone, so does Photos take this into account or can we just change the time and date according to what we think it is for the image independent of time zone?