[ballenf]

Each subtracted timeout is a 25 day timer, so any accumulated error would be miniscule. In your example there would a total of 2 setTimeouts called, one 25 day timer and one 15 day. I think the room for error with this approach is smaller and much simpler than calculating the date delta and trying to take into account daylight savings, leap days, etc. (but I don't know what setTimeout does with those either).

Or maybe I'm missing your point.

[zeroonetwothree]

You don’t need to take into account daylight savings or leap days when dealing with unixtime.