You can view your playtime using the /playtime chatcommand. The tracker is per-player, not for the whole server. You can view other player's playtime using /playtime [player name]. Every hour of playtime a user gets, the playtime will get announced to the server. The mod is compatible with all if not most games & mod(pack)s. While this mod works in minetest game it should be noted that it is meant to be used together with other mod(pack)s to keep track of or speedrun progress.
Advanced Playtime
Keeps track of playtime for all players in your world. Notifies you how much playtime you have occasionally.