The Gemara in Taanis says that when Av comes in, we minimize our joy, and R’ Yehuda, quoting others says, “Just as when Av enters we minimize our joy, when Adar enters we increase our joy.”
It discusses that in the month of Adar, our “mazel” rises, and if one has a court case in a non-Jewish court, Adar is a better time for him to go.
One reason to increase our joy is that Purim is a time of miracles, which leads to Pesach with more miracles.
In a year like this with two Adars, do we begin being “happy” from the first or the second Adar?
The mitzvos of Purim, including the special four parshios, are observed in the second Adar, because of its proximity to Pesach, thereby aligning the salvations.
However, there may be reason to be joyous in the first Adar as well, and indeed, noted poskim who wrote letters in Adar I would add the phrase, “Mishenichnas Adar Marbim B’Simcha” to those missives.
While the mitzvos of Purim are pushed back to the second Adar to correspond more closely to Pesach, from the beginning of Adar I we can expect miracles and take joy in knowing that Hashem can redeem us whenever He wants.
Being happy also improves our mazel, so the very fact we work to be more joyous brings the benefits of Adar!
