The Feast of Passover is on the fourteenth day at evening (beginning of the fifteenth biblical day) of the first biblical month to remember when they were delivered and when death passed over all who's house was covered by the blood of the Lamb.
This began on the evening of the fourteenth (beginning of the fifteenth day) day of the first month and lasted for seven days. The first evening is the Passover Feast.
The Feast of First Fruits takes place on the day after the second High Sabbath of the feast of Unleavened bread. (This also happened to be the first day of the new week when Jesus rose)
The Feast of Weeks falls exactly fifty days from the Feast of First Fruits. It’s seven Sabbaths and one day. This Holy day is also known as Pentecost which means fifty.
The Feast of Trumpets falls on the first day of the seventh month. It's a Holy day that is meant to be filled with joy and triumph. It’s celebrated by blowing trumpets and gathering together to rejoice and feast.
The day of Atonement sounds serious because it is. This Holy day is observed on the tenth day of the seventh month. It is a day of mourning, afflicting one's self and prayer.
The Feast of Tabernacles takes place on the fifteenth day of the seventh biblical month which falls sometime between mid September to the first half of October.