MongoDB query to search for Month and Day only?

To search for month and day only, use the aggregate framework.

Let us first create a collection with documents −

> db.monthAndDayDemo.insertOne({"LoginDate":new ISODate("2019-04-27")});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cefbcaeef71edecf6a1f6b2")
}
> db.monthAndDayDemo.insertOne({"LoginDate":new ISODate("2018-04-30")});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cefbcb7ef71edecf6a1f6b3")
}
> db.monthAndDayDemo.insertOne({"LoginDate":new ISODate("2018-04-27")});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cefbcbcef71edecf6a1f6b4")
}
> db.monthAndDayDemo.insertOne({"LoginDate":new ISODate("2016-04-27")});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cefbdaaef71edecf6a1f6b5")
}

Display all documents from a collection with the help of find() method −

> db.monthAndDayDemo.find();

Output

{ "_id" : ObjectId("5cefbcaeef71edecf6a1f6b2"), "LoginDate" : ISODate("2019-04-27T00:00:00Z") }
{ "_id" : ObjectId("5cefbcb7ef71edecf6a1f6b3"), "LoginDate" : ISODate("2018-04-30T00:00:00Z") }
{ "_id" : ObjectId("5cefbcbcef71edecf6a1f6b4"), "LoginDate" : ISODate("2018-04-27T00:00:00Z") }
{ "_id" : ObjectId("5cefbdaaef71edecf6a1f6b5"), "LoginDate" : ISODate("2016-04-27T00:00:00Z") }

Following is the query to search for month and day only −

{ "_id" : ObjectId("5cefbcaeef71edecf6a1f6b2"), "LoginDate" : ISODate("2019-04-27T00:00:00Z") }
> db.monthAndDayDemo.aggregate( { "$project": { "m":{"$month":"$LoginDate"}, 
"d": { "$dayOfMonth":"$LoginDate" } }}, { "$match":{ "m": 4, "d": 27 } } );

Output

{ "_id" : ObjectId("5cefbcaeef71edecf6a1f6b2"), "m" : 4, "d" : 27 }
{ "_id" : ObjectId("5cefbcbcef71edecf6a1f6b4"), "m" : 4, "d" : 27 }
{ "_id" : ObjectId("5cefbdaaef71edecf6a1f6b5"), "m" : 4, "d" : 27 }