Is the invitation dates from the 5th to some other date?
I've never seen a student visa invitation, so I'm not sure, but does it give a single date or a range of dates?
Does it say valid for xx days?
I only have experience with a personal invitation from family. My family member lists a range of dates for a 3 year period, for instance this last visa we listed July 02, 2025 to July 01, 2028. Then I just apply and the visa comes with the dates as shown on the invitation.
You can try going on You Tube and looking for student visa Russia and other searches like that. There is some good info on You Tube, but it is scarce.