Redirect from the group timetable that does not exist to the home screen instead of displaying HTTP 404

[Igifigi]

When you try to open group timetable that doesn't exist, you get HTTP 404. It'd more natural if you were redirected to the home page. Try this example: https://zorza.lo3.wroc.pl/timetable/groups/108,109,111,115,123,124/.

[DietPawel]

I think it is more UX issue, and the solution could be improved to conform to RFC7231. Please see:

The 404 (Not Found) status code indicates that the origin server did
not find a current representation for the target resource or is not
willing to disclose that one exists.

When talking about redirects it is generally rule that:

The 307/301 status code indicates that the target resource resides under a different URI

Which is false if that groupset is just bad.

How about customizing 404 page with additional information? Probably a link to subset of requested groups that exist could be useful.

[Igifigi]

Mostly when you try to access group timetable with non-existing groups, you are opening some sort of url/bookmark to the last-year timetable. I thinks the most natural behavoir would be redirect to main page where you can open or customize your timetable.