an alternative date when an event will take place if it has to be cancelled on the original date because of rain 遇雨改期日 July 15 is our annual fun day (rain date July 22). 7 月 15 日是我们一年一度的游乐日（遇雨则改至 7 月 22 日）。 He will announce a rain date by Monday. 他将在星期一宣布下雨日期。