I've create a mongoplayground to make it easier to understand.

If I just change '$$date' to its date:

Even if I insert the variable inside date function:

Does anyone have any thoughts in why it doesn't work in compass and works in mongoplayground?

CodePudding user response：

For best practice, when comparing date string, it is required to convert as date first (via $toDate).

$lte: [ { $toDate: "$date" }, { $toDate: "$$date" }]

Comparison/Sort Order (MongoDB Manual) - String section

By default, MongoDB uses the simple binary comparison to compare strings.

Hence, comparing dates in string format will lead to an inaccurate result.