Doomsday of a year

You will be presented with a year. Your task is to find the weekday that every doomsday in that year falls on. You will need several of the techniques from the previous games to pull this off.

The steps are as follows:

Find the anchor day

Determine the anchor day for the date.

Multiples of 12

Count how many whole 12s fit into the last two digits of the year.

Modulo 12

Find the remainder when the last two digits of the year are divided by 12.

Count of fours

The final number to keep in mind is the count of fours within that modulo 12 result.

Sum and modulo 7

Now, it’s time to combine the numbers we’ve collected and use the modulo 7 operation to determine the Doomsday of the given year.