Explanation
Working from the inside-out, the WEEKDAY function takes a date and returns a number between 1 and 7. With default settings, the number 1 corresponds to Sunday and the number 7 corresponds to Saturday.
The CHOOSE function simply maps numbers to values. The first argument is the number to map, and subsequent arguments represent associated values.
In this case, 7 values have been provided in the order required to work with WEEKDAY’s Sunday through Saturday scheme.
With a date from column B, WEEKDAY returns a number which is fed to the CHOOSE function. CHOOSE returns the value at that position in the list of abbreviations.
Explanation
In this case, Excel extracts the month from the date in cell B6 as a number, and the month in the cell C6 as a number, then tests for equivalency using the equal sign. Both dates are in January, so the formula is solved as follows and returns TRUE.
=MONTH(B6)=MONTH(C6)
=1=1
=TRUE
Same month as today
If you need to test a date to see if has the same month as the current date (today), you can use this formula:
=MONTH(date)=MONTH(TODAY())
Same month and year
To test that a date is the same month and year is another date, you can use this clever formula proposed by reader Eric Kalin :
EOMONTH(date1,0)=EOMONTH(date2,0)
