英文合同中常用的限定日期有：prior to 表示“某日之前，提前多少日”；on or before, no (not) later than,表示“不迟于”，on and after 表示从某日起

如：

1. To this end, prior to each meeting, members must declare any potential conflict of interest and sign a confidentiality agreement.

为此，每次会议之前，所有委员必须申报是否存在可能的利益冲突，并签订保密协议。

2. "Accounts Agreement" means the Accounts Agreement to be entered into among ABC INC., the Concessionaire and the Accounts Bank on or before the Commencement Date, as amended from time to time.

“账户协议”指即将由abc有限公司，特许经营公司与开户银行在生效日期当日或之前签订的协议，以及随时可能对其原文所做的修订。

3. Provided that if sent by mail, on and after seven days of mail as per the address which stipulated in this contract shall be deemed have been served.

通过邮寄送达的，一方按照本合同记载的地址投邮后经过七日，视为送达另一方。