1A set period of time for something, such as a contract or a stay.
このビザの有効期限は3年間です。
This visa is valid for a period of three years.
保証期限内であれば無料で修理します。
If it's within the warranty period, repairs are free.
契約の期限を1年延長した。
We extended the contract term by one year.
2A deadline by which something must be done; also used (as in 期限切れ) to mean that a time limit has passed.
申し込みの期限は今月末までです。
The application deadline is the end of this month.
支払い期限を過ぎると延滞料が発生する。
If you miss the payment deadline, a late fee will be charged.
パスポートの期限が切れる前に更新してください。
Please renew your passport before it expires.