Business Day

A day of the week, except Saturdays, Sundays, and holidays; a normal working day. Because of accepted custom and practice, the term business day is preferable to the term banking day or working day. 

Some laws require notice within five business days; for example, notice to quit for tenant’s failure to pay rent; other laws refer to calendar days. A dispute can arise if a contract fails to state whether the notice be within business days or calendar days, although the usual interpretation is that it is calendar days unless specified otherwise.