On Gatherer, I can see the original wording for Time Vault:
Tap to gain an additional turn after the current one. Time Vault doesn't untap normally during untap phase; to untap it, you must skip a turn. Time Vault begins tapped.
And I can see the most recent errata:
Time Vault enters the battlefield tapped.
Time Vault doesn't untap during your untap step.
If you would begin your turn while Time Vault is tapped, you may skip that turn instead. If you do, untap Time Vault.
Tap: Take an extra turn after this one.
Using Google, I was able to find a few more revisions:
Time Vault comes into play tapped.
Time Vault doesn't untap during your untap step.
Skip your next turn: Untap Time Vault and put a time counter on it.
T, Remove all time counters from Time Vault: Take an extra turn after this one. Play this ability if only there's a time counter on Time Vault.
Time Vault comes into play tapped.
Time Vault doesn't untap during your untap step.
At the beginning of your upkeep you may untap Time Vault. If you do, put a time counter on it and you skip your next turn.
T, Remove all time counters from Time Vault: Take an extra turn after this one. Play this ability only if there's a time counter on Time Vault.
Time Vault comes into play tapped.
If Time Vault would become untapped, instead choose one -- untap Time Vault and you skip your next turn; or Time Vault remains tapped.
T: Take an extra turn after this one.
... But are there any more versions? For the sake of historical curiosity, I'm interested in seeing every revision listed in one place.