Calendar days
Defined in 1 dictionary — Black's (1910)
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
So many days reckoned according to the course of the calendar. For example, a note dated January 1st and payable "thirty calendar days after date," without grace, is payable on the 31st day of January, though if expressed to be payable simply "thirty days after date," it would be payable February 1st.
Defined under Calendar in Black's Law Dictionary.