In truth, the New Moon is also called a Festival...
(1) בראשית IN THE BEGINNING — Rabbi Isaac said: The Torah which is the Law book of Israel should have commenced with the verse (Exodus 12:2) “This month shall be unto you the first of the months” which is the first commandment given to Israel...
וַיִּגְזֹר בָּהּ גְּזֵרָה גְמוּרָה עַל־שַׁבָּת רֹאשׁ־חֹֽדֶשׁ וּמִילָה:
Megillat Antiochus 32
And he issued a severe decree banning, the Sabbath, the new moon, and circumcision.
(ד) בָּרוּךְ אַתָּה יְיָ אֱלֹהֵינוּ מֶלֶךְ הָעוֹלָם, אֲשֶׁר בְּמַאֲמָרוֹ בָּרָא שְׁחָקִים וּבְרוּחַ פִּיו כָּל צְבָאָם. חֹק וּזְמַן נָתַן לָהֶם שֶׁלֹּא יְשַׁנּוּ אֶת תַּפְקִידָם. שָׂשִׂים וּשְׂמֵחִים לַעֲשׂוֹת רְצוֹן קוֹנָם. פּוֹעֵל אֱמֶת שֶׁפְּעֻלָּתוֹ אֱמֶת. וְלַלְּבָנָה אָמַר שֶׁתִּתְחַדֵּשׁ, עֲטֶרֶת תִּפְאֶרֶת לַעֲמוּסֵי בָטֶן, שֶׁהֵם עֲתִידִים לְהִתְחַדֵּשׁ כְּמוֹתָהּ וּלְפָאֵר לְיוֹצְרָם עַל שֵׁם כְּבוֹד מַלְכוּתוֹ. בָּרוּךְ אַתָּה יְיָ, מְחַדֵּשׁ חֳדָשִׁים:
Blessed are You Hashem, our God, Master of the Universe, who with His word created the heavens, and with His breath all of its hosts...And to the moon He says "Renew!", a glorious crown for those borne of the womb, who will ultimately renew themselves like the moon and glorify their Creator...