There are three celebrations which God gave to His people where they are to meet together to worship God and celebrate:
14 “Three times a year you are to celebrate a festival to me.
15 “Celebrate the Feast of Unleavened Bread; for seven days eat bread made without yeast, as I commanded you. Do this at the appointed time in the month of Abib, for in that month you came out of Egypt. “No one is to appear before me empty-handed.
16 “Celebrate the Feast of Harvest with the firstfruits of the crops you sow in your field. “Celebrate the Feast of Ingathering at the end of the year, when you gather in your crops from the field.
17 “Three times a year all the men are to appear before the Sovereign LORD.
(Exo 23:14-17 NIV)
An article explaining this is found at jewishvoice.org These three appointments were Pesach (Passover), Shavuot (Pentecost), and Sukkot (Tabernacles). In addition to these three, God added four additional times of celebration in Leviticus 23, thereby making a total of seven biblical festivals. Matzah (Unleavened Bread) and Bikkurim (Firstfruits) were to be celebrated immediately after Passover.
120 Years: