Max Stay Check In
This ensures that guests checking in on that particular night stay for a maximum of X nights (or less). For example, a maximum stay check in rule of five on a Friday means that guests must check out by Wednesday morning.

Max Stay Any
This ensures that guests staying on that night (regardless of when they checked in) stay for a maximum of X nights (or less). For example, a maximum stay any rule of five on a Friday means that guests checking in on Monday, Tuesday, Wednesday, Thursday and Friday can only stay a maximum of five nights.