Database
[{date:new Date("2019-11-13T00:10:00Z"),},{date:new Date("2019-11-13T00:12:00Z"),},{date:new Date("2019-11-13T00:22:00Z"),},{date:new Date("2019-11-13T00:37:00Z"),},{date:new Date("2019-11-13T00:47:00Z"),},{date:new Date("2019-11-14T00:15:00Z"),}]
Query
db.collection.aggregate([{$bucket:{boundaries:[new Date("2019-11-13T00:00:00Z"),new Date("2019-11-13T00:15:00Z"),new Date("2019-11-13T00:30:00Z"),new Date("2019-11-13T00:45:00Z"),],default:"outOfRange",groupBy:"$date",output:{count:{$sum:1}}}},])