God says the day does matter.
The word of God gives us a celebration for his son’s birth, the day he came to Tabernacle with us. It was the 15th day of the Biblical month Tishri, which places his birth in September by our calendar.
YHVH doesn’t tell us things that don’t matter. If we ignore the rehearsals that YHVH prescribed, we will not be ready when it isn’t a rehearsal any more. Sukkot is when he will return, but which Sukkot? This is what the parable of the virgins is all about; those that ignore Sukkot, and pretend that he was born on Tammuz’s birthday are the foolish virgins. Do you wish to be one of them?
“..God says the day does matter...
Yes the day does matter - Jesus was born on the longest night of the year - the Light of the World came on the darkest night.
See John Chapter 1 verses 4 and 5. He was born on the pagan holiday to bring light to the pagan minds. Google 1622 painting by Gerard van Honthorst, Adoration of the Shepherds for a visual.