Leviticus 23:37
"'These are the appointed feasts of Yahweh, which you shall proclaim to be holy convocations, to offer an offering made by fire to Yahweh, a burnt offering, and a meal offering, a sacrifice, and drink offerings, each on its own day;
Leviticus 23:2
"Speak to the children of Israel, and tell them, 'The set feasts of Yahweh, which you shall proclaim to be holy convocations, even these are my set feasts.
Leviticus 23:4
"'These are the set feasts of Yahweh, even holy convocations, which you shall proclaim in their appointed season.
Deuteronomy 16:16-17
Three times in a year shall all your males appear before Yahweh your God in the place which he shall choose: in the feast of unleavened bread, and in the feast of weeks, and in the feast of tents; and they shall not appear before Yahweh empty:
Ecclesiastes 3:1
For everything there is a season, and a time for every purpose under heaven: