The Seven Feasts of Israel are also referred to Holy Scripture as the 'Feasts of the Lord'. 
For an excellent introduction to the 7 Feasts and the Hebrew Calendar see the YouTube video by CarrieAnn from a Messianic fellowship.

7th - Feast of Tabernacles

6th Feast is Day of Atonement

5th - Feast of Trumpets

4th - What is Pentecost?

3rd - Feast of Firstfruits

2nd - Unleavened Bread

1st - Passover