How to calculate timestamp difference in mongodb (in hours)?

Question

Here\'s my data:

[
   {
       id: 1, 
       starttime: ISODate(\"2015-08-24T00:00:00.000Z\"), 
       endtime: ISODate(\"2015-08-24T07:00:00.000Z\")
   },         


        

Answer 1

db.collectionname.aggregate([
  {$project: {
      duration: {$divide: [{$subtract: ["$endtime", "$starttime"]}, 3600000]}
  }}
])