Masters Edition II

Time Bomb

At the beginning of your upkeep, put a time counter on Time Bomb.
{1}, {T}, Sacrifice Time Bomb: Time Bomb deals damage to each creature and each player equal to the number of time counters on Time Bomb.

At the beginning of your upkeep, put a time counter on this artifact.
{1}, {T}, Sacrifice this artifact: This artifact deals damage equal to the number of time counters on it to each creature and each player.

Fifth Edition

During your upkeep, put a time counter on Time Bomb.
o1, oc
T, Sacrifice Time Bomb: Time Bomb deals to each creature and player an amount of damage equal to the number of time counters on Time Bomb.

Ice Age

During your upkeep, put a time counter on Time Bomb.
o1,oc
T: Sacrifice Time Bomb to have it deal * damage to each creature and player, where * is equal to the number of time counters on Time Bomb.