在合同条款中，虽然其有“有时，偶尔”的意思，但“from time to time”通常翻译成“不时，届时”，比如“as currently in force and as amended from time to time”，可以翻译成“按照现行及不时修订的相关有效之(规例/法律/条例...)..."。

The letter shall be delivered to such address as one Party may from time to time notify to the other Party.

函件应由一方递送至另一方届时通知的地址。

A Party may change its designated Project Manager by written notice from time to time.

一方可通过不时书面通知变更其指定的项目经理。