DateDifference

DateDifference[date₁, date₂]
gives the number of days from date₁ to date₂.

DateDifference[date₁, date₂, "unit"]
gives the difference between date₁ and date₂ in the specified unit.

DateDifference[date₁, date₂, {"unit₁", "unit₂", ...}]
gives the difference as a list with elements corresponding to the successive "unit_i".

	{y,m,d}	year, month, day
	{y,m}	the first day of the specified month
	{y}	January 1 of the year y
	"string"	date as a string ("Jan. 1, 2000")
	{y,m,d,h,m,s}	precise time
	time	absolute time specification

Possible units are "Year", "Quarter", "Month", "Week", "Day", "Hour", "Minute", "Second".

DateDifference[date₂] gives the fractional number of days from the current time until date₂.

Give the number of days between January 1 and July 4:

Use dates specified in {y, m, d} form:

Find a date difference in units of weeks:

If the second date is before the first, the date difference is negative: