n. 期间；时期；时代
period bill 定期票据，定期汇票
period charges 当期费用
period contract 契约有效期，合同有效期
period of adjournment 休会期，休庭期
periodof employment 雇佣期间
period of priority 优先期
例1：
This Agreement shall be valid and remain in force for a period of three (3) years commencing from the date appearing first above written upon the signing of both Party A and Party B and shall be extended for another period of three (3) years on the same terms and conditions unless either of the parties hereto gives the other party at least thirty (30) days prior written notice to terminate this Agreement prior to the expiration of the original term.
本合约须从上面首次写明的甲方和乙方签订本约的日期起生效并保持效力三年，并将按同样条件延长三年，否则与约任何一方至少须在原定时间期满前三十天给予另一方提前终止本合约的书面通知。
例2：
At any time and from time to time during the period commencing on the date hereof and terminating on ______, 20___, party A may in writing advise party B.
自本协议签订之日起到______年______月协议终止这段期间内，甲方可随时以书面形式通知乙方。
