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 "uniti".

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