[{"startDate":{"$date":{"$numberLong":"1630926969195"}},"endDate":{"$date":{"$numberLong":"1648558585308"}}}]

db.collection.aggregate([{"$project":{_id:0,totalHours:{"$dateDiff":{"startDate":"$startDate","endDate":"$endDate","unit":"hour"}},totalMinutes:{"$dateDiff":{"startDate":"$startDate","endDate":"$endDate","unit":"minute"}},totalSeconds:{"$dateDiff":{"startDate":"$startDate","endDate":"$endDate","unit":"second"},},days:{$toInt:{"$dateDiff":{"startDate":"$startDate","endDate":"$endDate","unit":"day"}}}}},{$addFields:{hours:{"$subtract":["$totalHours",{"$multiply":["$days",24]}]},}},{"$addFields":{minutes:{"$subtract":["$totalMinutes",{$add:[{"$multiply":["$days",24,60]},{"$multiply":["$hours",60]}]}]}}},{"$addFields":{seconds:{"$subtract":["$totalSeconds",{$add:[{"$multiply":["$days",24,60,60]},{"$multiply":["$hours",60,60]},{"$multiply":["$minutes",60]}]}]}}},{$project:{"totalHours":0,totalMinutes:0,totalSeconds:0}}])