Seven festivals represent the seven aspects of the formation of the spiritual world, just as the seven days of the week represent the seven stages of the creation of the physical world.
אלה הם מועדי (כג:ב)
ששת ימים (כג:ג)
וביום שביעי And the Seventh Day
DAY OF CREATIONCONNECTIONHOLIDAY1Yom Echad
HaShem alone;
Special Light of first day hidden away
HaShem Himself struck the First Born (no angel);
First night of Exodus, light from first day shone
First day of Pesach2Firmament created separating between the waters; Splitting of the Reed SeaLast day of Pesach3Origin of fruit-bearing trees; HaShem judges the future fruit harvestShavuos4Heavenly bodies created; Beginning of yearly cycleRosh Hashana5Day’s creations issued from the waters, including the Levithan
Water libations and special prayers for water, life-source of all;
Sukah to be made out of skin of Levithan
Sukkos6HaShishi
Creation of Man; purpose of Creation
Celebrate the Torah as observed by man
Shmeni Atzeres7Creation of Shabbos
HaShem forgave Adam HaRishon
Shabbos Shabbason
Ochel Nefesh forbidden
HaShem forgives the Jewish Nation
Yom HaKippur