If you are only looking for silver and buffalos, you don't have to date check.
You can greatly improve your efficiency by looking at only one side of the coin - whichever side is facing you.
If you are facing the obverse, look at the date.
If you are facing the reverse, look for the mint mark. If you see a large D/P/S above the dome, its a keeper. If you see a small D or small S to the right of the dome, flip it over and check the date to see if it is a keeper if you want to. If there is a no mint mark on the reverse but the toning or depth of relief seems "different," flip it over and check the date if you want to.
You will miss some older date Philly nickels this way but if you are in it mostly for Ag, you'll get through nickels 30% faster. Obviously, you'll find foreigns, Buffalos, and V nickels this way just like you would date checking.