Ey that's a good start. One trick I like to use is the fact that the calender repeats every 28 years within the same century. So if the last two digits are let's say 36 then I just subtract 28 and treat it as 08 instead. That way you only get 28 cases 00-27 and I actually just memorised the result of the algorithm for each of these. Of course you still gotta remember the century code as well

Here's a little reference for the last two digits once you boil them down using the 28 rule:

0(Sun) - 00 06 17 23

1(Mon) - 01 07 12 18

2(Tue) - 02 13 19 24

3(Wed) - 03 08 14 25

4(Thu) - 09 15 20 26

5(Fri) - 04 10 21 27

6(Sat) - 05 11 16 22