How Do I Put the Right Date on Old Scanned Photos?
Set an approximate date per batch. A photo dated 1974 sorts far better than one dated today.
You will rarely know the exact day, and it does not matter. Scan a box at a time, guess the year, and write that in. A photo dated 1 January 1974 sits in the right decade and the right place in the story.
Work in batches by album or envelope. Anything written on the back is worth typing into the filename while you have it in your hand.
Takeout JSON Metadata Fixer can stamp a whole folder with a date and build filenames from it, so a scanning session becomes one organized folder. It runs on your own computer and is free for your first 500 photos.