db={"teacher":[{"_id":"6434cf","start_time":ISODate("2023-03-22T07:00:25.787Z"),"end_time":ISODate("2023-03-22T10:00:35.604Z"),"duration":"15min","time_slots":[{"sl_no":1,"dateTime":ISODate("2023-03-22T06:30:25.787Z")},{"sl_no":2,"dateTime":ISODate("2023-03-22T06:45:25.787Z")}],},{"_id":"6434ctd","start_time":ISODate("2023-03-23T07:00:25.787Z"),"end_time":ISODate("2023-03-23T10:00:35.604Z"),"duration":"20min","time_slots":[{"sl_no":1,"dateTime":ISODate("2023-03-23T06:30:25.787Z")},{"sl_no":2,"dateTime":ISODate("2023-03-23T06:50:25.787Z")}],}],}

db.teacher.update({_id:"6434cf"},[{$set:{start_time:{$dateAdd:{startDate:"$start_time",unit:"minute",amount:60}},end_time:{$dateAdd:{startDate:"$end_time",unit:"minute",amount:60}},time_slots:{$map:{input:"$time_slots",in:{sl_no:"$$this.sl_no",dateTime:{$dateAdd:{startDate:"$$this.dateTime",unit:"minute",amount:60}}}}}}}])