Adding/Subtracting days to ISODate in MongoDB Shell

Question

I have a query where I need to get events that are one day before or after from a specific date. I need to add or subtract one day to that ISODate variable. Here is my query :

db.event.find().forEach( function (x) {    print("x : " + x.EventID + ", " + x.ISODate);    db.events.find( {    "$or" : [{        "StartDate" : { "$gte" : x.ISODate } // Here i need to subtract one day        }, {            "EndDate": { "$lt" : x.ISODate} // Here i need to add one day            }] }).forEach(function(otherDay) {         print("x.EventID : " + x.EventID + ", other.Date : " + otherDay.StartDate + " - " + otherDay.EndDate);       });  }); 

How can i add or subtract days to an ISODate variable in mongodb shell?

Answer 1

Not an exact answer but related.

I needed to increment a date field for all items in my MongoDB collection in place, relative to the date value that was stored.

The query below will add 1 day to myDateField in myCollection.

db.myCollection.find().snapshot().forEach(     function (elem) {          const dateDiffInMs = 1 * 24 * 60 * 60000          db.myCollection.update(             {                 _id: elem._id             },             {                 $set: {                     myDateField: new Date(elem.myDateField.getTime() + dateDiffInMs)                 }             }         );     } ); 

---

1 day = 1 * 24 * 60 * 60000 = 1 x 24 hours x 60 minutes x 60 seconds x 1000 milliseconds 

• Use minus value for dateDiffInMs if you need to subtract / go back in time.

Answer 2

This has been answered on Query to get last X minutes data with Mongodb

query = {     timestamp: { // 18 minutes ago (from now)         $gt: new Date(ISODate().getTime() - 1000 * 60 * 18)     } } 

And in your case, for a number of days:

"StartDate" : { "$gte" : new Date(ISODate().getTime() - 1000 * 3600 * 24 * 3) } 

or

"StartDate" : { "$gte" : new Date(ISODate().getTime() - 1000 * 86400 * 3) } 

(here the 3 is your number of days)