Special Absence Code

Dear Experts,

As per business requirement I suppose to create a special absence code which it needs to work only for Sunday.

As per WS few Sunday are regular working days, so for these Sunday client as raised to create new absence code which needs to work only these Sundays.

I have tried in table T556C table but I did not succeeded, because it's allowing other than Sundays also.

Please guide me the right direction.