Shopping613,
“Why is it a holiday “given to the women”?”
My understanding is that Rosh Chodesh was given because the women in the midbar did not panic like the men who thought Moshe Rabbeinu had died, a time when things seemed really dark like the moon becomes dark immediately prior to Rosh Chodesh, and they refused to give over their gold. They continued to have faith that the light of Hashem’s promises would come. Due to this, Jewish women merit Rosh Chodesh, which stands at the doorway of the transition from the dark new moon to the bright full moon.