What time is it in Ushuaia?

Argentina spans 12 time zones, so the answer depends on where in it you mean. Ushuaia covers tierra del fuego (tf) and is on the same clock as Buenos Aires, though the two are separate zones in the IANA database and can diverge when daylight saving rules differ.

Ushuaia does not observe daylight saving, so its offset from UTC never moves. Its relationship to places that do change shifts twice a year instead.