How to Calculate the Month when you have the Day, Year and Day-of-Week.
Calculate Steps 1 through 3 of the Day-of-Week technique, using 0 (zero) in Step 1 for the Month, then calculate Step 4, below, using the resulting (result) value from those steps.
Step 4 – Look up the known Day of the Week for the Target Date in the Day-of-Week Table. If the Result is greater than the value for the target Day-of-Week, add 7 to that target Day-of-Week value. Now subtract the Result from the adjusted Day-of-Week value. This result is the value for the target Month you are looking for in that year, of which there will be at least one, maybe more. Look up all the months with that value in the Month Table, remembering to subtract 1 for January and February (i.e., January is 6 and February is 2).
For an example using January 11, 1988, click here (see parts I and II only).
For an example using January 11, 1988, click here (see parts I and II only).
