Well... there's 328 days, and 11 months, anywhere between 27 and 32 days in a month. Seven days a week, like it sounds you've got too.

[A faint tilt of his head as he counts off on his fingers.]

Miresen, Grissen, Whelsen, Conthsen, Folsen, Yulisen, and Da'leysen. I think I remember hearin' it was a real old elven calendar from way back that folk just kinda started adoptin' all over?