John and Nora met at a health club.

(A) John started going to the health club on the first Monday in January and thereafter, he went every fifth day.

(B) Nora started going to the health club on the first Tuesday in January and thereafter, she went every fourth day.

(C) John and Nora went to the health club on the same day just once in January; it was on that day that they met.

On which day of January did John and Nora meet?