Sort By Time Of Day

// Sorts input date/time wave by the time of day. NaNs (blanks) go to the end.
// NOTE: This overwrites the input wave.
Function SortByTimeOfDay(w)
	Wave w					// Date/time wave to be sorted
	
	Duplicate/FREE w, timeOfDay
	timeOfDay = mod(w, 24*60*60)		// timeOfDay now contains just time of day
	Sort {timeOfDay,w}, w			// Sort w by timeOfDay, then by date
End