Why do my snaps have the wrong date?

It comes down to where the information lives. A picture from an ordinary camera carries its date inside the file, in something called EXIF data. That is why photo apps can sort chronologically without knowing anything about the filename. The date travels with the picture wherever it goes.

Snapchat's export works differently. Dates and locations are included in the export, but in accompanying data rather than inside the picture or video file itself. So when you import the files, your photo app sees no date at all and falls back on the only thing it has: when the file was created on disk. Which is the day you downloaded it.

The result is that several years of memories land on a single day in your timeline. Pictures from 2018 sit mixed in with yesterday's, all sorted as though they happened at the same moment, in a pile of filenames like b8f2c1a9.mp4 that say nothing about what they contain.

For many people that is worse than never having taken anything out, because it wrecks the order of a photo library built up over years. Cleaning it up by hand afterwards is not realistic. Nobody sets the date on twelve thousand files one at a time.

What we do is read the date and the position out of the export's data and write them back into the file where they belong. After that, the memories behave like ordinary photos: the right place in the timeline, the right place on the map, filenames that make sense.

One important detail: how exact the date gets depends on what your export contains. If you have the JSON files with you, we get dates with times and GPS. If they are missing, all we can read is the day from the filename. The archive comes out in the right order, but with no time of day and no map. That is why that one tick box matters so much.