I need an Excel formula to convert a date (mm/dd/yyyy) to a serial number,
i.e. January 1st = 001, 1st February = 032, 31st and so on to December 31st =
365 . The serial number needs to reset to 001 on Jan 1st of each new year.

Is there a quick way to convert any given date from any given year to this
3-digit day number?

Thanks in advance,
Rodney