Mongo shell query using date

I'm trying to run this Mongo shell query from a linux bash. The problem is that I can't check if a date in Mongo is greater than a "date" stored in a bash script variable.

This runs fine:

counter=$(mongo --quiet dbName --eval 'db.dbCollection.find({"updatedAt":{"$gt":ISODate("2019-02-01T00:00:00.000Z")}}).count()')

And the "counter" var has the expected value. But I can't use a fix value for the date. So, I created a var to store a date.

DATE2=$(date -d '1 minute ago' "+%Y-%m-%dT%H:%M:%S.%3NZ");

This date var has the expected value. I can see that using a simple printf.

Now, the modified code, using the DATE2 instead of a fix date, won't work because the query returns "0" when it should return "1".

counter=$(mongo --quiet dbName --eval 'db.dbCollection.find({"updatedAt":{"$gt":"$DATE"}}).count()')

I've tried to modify the code above, using IsoDate() and other things, but nothing seems to work.