Why don't astronomers use everyday units to measure distances (what is an AU or a pc)? (Intermediate)
How this formula works: The WEEKNUM function takes two arguments, a date, and, optionally, an argument called return_type, which controls the scheme used to calculate the week number. See the WEEKNUM page for more information. B4 contains a date value for January 5, 2016. The DAY function returns the number 2 representing the calculated week number. Note that by default, the WEEKNUM function uses a scheme where week 1 begins on January 1, and week 2 begins on the next Sunday (when the return_type argument is omitted, or supplied as 1).
Assuming months are in column B, from B3 to B14, last working day of first month can be found by WORKDAY() formula: =WORKDAY(B4,-1) . WORKDAY() excel formula calculates a future / past date by adding / subtracting any number of working days from it.