Setting time and date for Photos ap

> shows a date in the future for all the new photos I upload

What do you mean by "upload"? Upload from where to where?

What do you mean by "future" date? A date like 2038 or just too much to the future like 2023 instead 2019?

Anyway, you can shift the dates via Photos.app > Image > Adjust Date and Time...

If all dates are incorrect, then maybe the images do not have a correct internal metadata date. Or not any internal metadata date at all (social media sites like WhatsApp, Facebook etc usually delete metadata). If that is the case, then Photos as a last resort grabs the date from the very fragile file create date (that might very well be something like 2038).

If you are importing the photos from a camera, you may want to check settings of your camera for the date and time and location, so the next import will be correct.