我怎样才能将这个伪代码转换成可用的JS[除了它是一个有效的JavaScript日期外,不要担心结束日期来自哪里]。varmyEndDateTime=somedate;//somedateisavalidJSdatevardurationInMinutes=100;//thiscanbeanynumberofminutesfrom1-7200(5days)//thisisthecalculationIdon'tknowhowtodovarmyStartDate=somedate-durationInMinutes;alert("Theeventwillstarton"+myStartDa