HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

start - time for the first turn,
turn - time added to each subsequent turn
unused time from a turn is carried over to the next
battle - time added to a battle
unused time from a battle is deducted at the end of the battle.

I tested HD on Heroes 7 with maximum UAC enabled:
it only requires administrator permission to make changes to the computer when installing. It launches and runs without asking for anything else. It does not require running as administrator. Win 7 Home Premium license.