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

so that you can see the remaining duration of the spell.

In my opinion, this should not be allowed in any of the versions: if this allows you to obtain information about whether the enemy hero has artifacts that increase the duration of the spell, then it is a guaranteed cheat. An extra round of magic, being a surprise to the opponent, can cost the game.