Information gathered from Leviticus 16, Leviticus 23, Numbers 29, Deuteronomy 16

In the 1st month (Nisan/Abib), 14th day of that month, at twilight: LORD’s Passover. 

In the 1st month (Nisan/Abib), 15th day of that month: Feast of Unleavened Bread, which takes place for seven days. On the seventh day of Feast of Unleavened Bread there are several offerings to the LORD.

The very next Sabbath that occurs after the offerings, is the first Sabbath of 7 Sabbaths that must be counted off.

From the 7th completed Sabbath, 50 days are then counted off.  This is the beginning of the Feast of Weeks or Pentecost (in the month of Sivan).

The seventh month of Tishrei, on the 1st day is the Feast of Trumpets.

The seventh month of Tishrei,  on the 10th day is the Day of Atonement (Yom Kippur) .

The seventh month of Tishrei, 15th day is the first day of Feast of Booths, and it is celebrated for 7 days. One of the more interesting ceremonies for this feast is that the Jews lived in “booths” (temporary, rustic shelters made out of tree boughs) for those seven days. This was to remind them that when they were brought out of Egypt by God, they lived in those types of temporary dwellings.