1. REDIRECT

"Octave" has two senses in Christian liturgical usage. In the first sense, it is the eighth day after a feast, reckoning inclusively, and so always falls on the same day of the week as the feast itself. The word is derived from Latin octava (eighth), with dies (day) understood. In the second sense, the term is applied to the whole period of these eight days, during which certain major feasts came to be observed.