This change will result in dates before epoch (01-01-1970) with millisecond precision , when used in $dateAdd, $dateSubtract, $setWindowFields, and $densify, being one second greater.

Description of Linked Ticket

The dateAdd() function defined in date_time_support does not always return the original date when it is given the value 0 to add. This affects results of the $dateAdd expression and can cause $setWindowFields failures due to bounds being computed incorrectly using the dateAdd helper function when a window function has bounds [0,0].

Original ticket description:

See discussion here and in the other comments on the ticket.

When running a $setWindowFields (regardless of window function), with a range-based upper bound of 0, we exclude the current document. We should be including it. When running a $setWindowFields with a range-based upper bound of "current", we correctly include the current document.

I have attached a js test file that can be used to reproduce this.

After fixing this bug, we should also add tests to jstests/aggregation/sources/setWindowFields/min_max_scaler_parsing.js for range-based boundaries with 0 and "current" as the upper bound.