Is Time Bomb legal in Standard, Modern, and Commander?

Time Bomb is legal in: Legacy, Vintage, Commander.

What type of card is Time Bomb?

Time Bomb is an Artifact. Its oracle text reads: "At the beginning of your upkeep, put a time counter on Time Bomb.{1}, {T}, Sacrifice Time Bomb: Time Bomb deals damage equal to the number of time counters on it to each creature and each player."

Time Bomb

Artifact

At the beginning of your upkeep, put a time counter on Time Bomb.<br>, , Sacrifice Time Bomb: Time Bomb deals damage equal to the number of time counters on it to each creature and each player.