Suppose we have a bunch of days and we want Excel to dynamically calculate their difference from today's date, whatever that might be. Obviously, "today" changes every day, so is there a way Excel can keep the calculation current?
Meet the TODAY() function!
If we take a random set of dates in one column,
and then provide the TODAY() function in another column,
the third column can subtract the today's date from the other date to get a past (negative) or future (positive) difference in days.