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).
To subtract a number of months or years to a date, you first need to decompose the initial date into its year, month, and day components, subtract the desired offset, and then let Excel put the components back together. For example, say you have a date in A1, to which you want to subtract 3 months and 4 days.or example, adding 6 months and 10 days to 8/25/97, in A1 with the formula. =DATE(YEAR(A1),MONTH(A1)+6, DAY(A1)+10). Generally, you cannot add two dates that are in serial format. For example, adding 1/15/1998 and 6/15/1998 gives 6/30/2096, which is essentially meaningless.