If you explicitly intended, at the time you took the oath, for it to have an expiration date or condition-- then it has an expiration date or condition. Even if that was not explicitly stated in the oath or vow (although in future, it is a good thing to explicitly express these things in writing or verbally, according to the form of the vow or oath--since at least in some instances failing to express such conditions can make a vow or oath invalid, or even count as a sin against the 8th commandment).
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If the expiration date or condition was not thought up until after the oath or vow was taken, then it's a different matter.
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I'm basing this on the Church's attitude toward marriage vows. If someone has an interior contradictory intention, condition, or expiration date for their vow then this factors as evidence to the nature and character of the vow.
ETA: supplied jurisdiction has nothing at all to do with it.