Database
[{"startDate":{"$date":{"$numberLong":"1630926969195"}},"endDate":{"$date":{"$numberLong":"1648558585308"}}}]
Query
db.collection.aggregate([{"$project":{_id:0,hours:{"$dateDiff":{"startDate":"$startDate","endDate":"$endDate","unit":"hour"}},minutes:{"$dateDiff":{"startDate":"$startDate","endDate":"$endDate","unit":"minute"}},seconds:{"$divide":[{"$dateDiff":{"startDate":"$startDate","endDate":"$endDate","unit":"second"},},1000]},days:{"$dateDiff":{"startDate":"$startDate","endDate":"$endDate","unit":"day"}}}}])