[5] The Highest Wisdom also decreed to give Israel additional sanctity by granting them holy days other than Shabbos, when the Jew receives various levels of holiness. None of these holy days, however, have as much Influence and sanctity as Shabbos.
The degree to which a person must abstain from worldly occupations on these days depends on the level of their Influence. Various types of work are therefore forbidden on many of these days.
Yom Kippur is the highest of these holy days, and therefore the prohibition against work is the most severe.
Below this are the other festivals, and on a still lower level, their intermediate days (Choi ha-Mo’ed).
Lower yet is the New Moon (Rosh Chodesh), when only women abstain from work.
Finally, there are Chanukah and Purim, when work is not curtailed at all. On Chanukah thanks are offered, and in addition to this, Purim is a time of joy. All these levels depend on the particular sustenance granted, which is the spiritual Light that shines on that particular day.
[6] Besides the sanctification that exists to various degrees depending on the holiness of each particular day, there is another concept that is specific to each one.
On each of these special days, something happened whereby at this time a great rectification was accomplished and a great Light shone. The Highest Wisdom decreed that on every anniversary of this period, a counterpart of its original Light should shine forth, and the results of its rectification renewed to those who accept it.
We are therefore commanded to observe Pesach with all its rituals to recall the Exodus. At the time of the Exodus, we experienced an extremely great rectification, and therefore, on the anniversary of this event, there shines forth a Light that parallels the one that illuminated us then. Since the results of that rectification are renewed in us, we are obliged to keep all these rituals.
Shavuos likewise involves a great rectification, since it is the time when the Torah was given.
Sukkos involves the Clouds of Glory, as it is written (Vayikra 23:43), “That future generations may know that I made the children of Israel dwell in sukkos Even though this is not celebrated on the anniversary of the Exodus, the Torah set a time that is appropriate for its commemoration.
Chanukah and Purim also involve this same concept. The is true of the days mentioned in the Scroll of Fasts (Me. Ta’anis). These were annulled, however, because the could not abide by them, and were therefore exempted commemorating them to stimulate their original light.
Translation from the Way of G-d – Feldheim
Here are the dates and approximate year of the Yomim Tovim
3924 BCE – Creation of the physical universe
3924 BCE – Creation of man: – Rosh Hoshana (1st of Tishrei)
3924 BCE – Rest from Creation – Shabbos
1476 BCE – Exodus from Egypt – Passover – 1st day (15th of Nissan)
1476 BCE – Splitting of Red Sea – Passover – last day (22th of Nissan)
1476 BCE – Receiving Torah at Mount Sinai – Shavuos (6th of Sivan)
1476 BCE – Golden Calf & Breaking of 1st Tablets- (17th of Tammuz)
1476 BCE – Second Set of Tablets – Yom Kippur (10th of Tishrei)
1476 BCE – Return of Clouds of Protection – Succos (15th of Tishrei)