What is the getdate() equivalent for MongoDB?

Question

I have a query to update and set some values in some fields.

Obut Now I need to update these field and in adition, I need to set DateOfModification to the current date and time.

What is the equivalent to GETDATE() from sql server to use in a $set?

I tried this:

db.col.updateMany({
     "field.field":"zzzzzzzz" 
},{$set:{
        "field2" : {
        "field3" : ObjectId("5d4dc2c2b3e6de001b934ec6"), 
        "field4" : "xxxxxxxxxxxxxxxxxxxxxxxxxx"
        },
        "DateOfModification: "$$NOW"
    }
}})

but It seems the $$NOW only works with mongoDB 4.2 and I'm still using 4.0

Thanks

Edit:

I tried $currentDate but still getting errors:

db.testeDBA.update(
        {},
          {$set: {"item":"anything",$currentDate: {"modifiedOn":true}}      
        })
        

'The dollar ($) prefixed field '$currentDate' in '$currentDate' is not valid for storage.+

Answer 1

You can try this.

db.testDBA.updateOne(
   {},
   {
     $currentDate: {
        modifiedOn:true
     },
     $set: {
        "item":"anything"
     }
   })

I inserted a new document and updated it. It worked.

If I run this code again, the document will be updated like this