Weekend would be E and A.
12 months of 6 weeks each, except "February" with an extra week.
A would always the 1st, 6th, 11th, 16th, 21st, 26th or 31st (in "February").
B would always be the 2nd, 7th, etc.
Leap years would have a day F inserted between E and A at the end of "February" (of which it would be the 36th), keeping this new calendar consistent with the current one.