When Out of Time enters the battlefield, untap all creatures, then those creatures phase out (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.) until Out of Time leaves the battlefield. Put a time counter on Out of Time for each creature that phased out this way.
Vanishing (This permanent enters with time counter(s) on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)