Preventing load from earlier version of game

I will try explain this. Since my game is in development and I update it a lot (every 15-20 days new version comes out) When I update game I also offer new saves (new game as autosave) and state where last version has ended, so that works for anyone who read my read me files etc... But, there are many people who will anyway try to load old saves (from previous version) and those can and most likely will make many bugs/glitches in game. So to make this not possible, I was thinking would it be possible to make Lua script that will read newgame state (in my case bookmark01) and date when it was created, when we open load screen or click new game (I set my new game with "default" if autosave does not exit make autosave if it exist load autosave). This way if it is possible to Lua read date of bookmark01 and if it is older then date xx.xx.xxx then (call action). I would for example set new object appear with red X on save game slot preventing player to load that old save... Anyway, since I am really noob for scripting in Lua, if this is possible, how it would look like? Thank you in advance.