HolyDays - Appointed Times
"These are the Appointed Times of YHWH which you proclaim as qodesh (holy) gatherings. Besides the Shabbath of YHWH, and besides your gifts, and besides all your vows, and besides all your voluntary offerings which you sacrificed to YHWH. Thus did Mosheh (Moses) speak of the Appointed Times of YHWH to the children of Yisra'el (Isreal)."
-Wayyiqra (Leviticus) 23:37-38, 44