Hallisan's Dawn is on the 1st day of the Hallisan's Zodiac which is concurrent with the 11th day of Harvesting on the Secular Calendar.
"In Fumaya, we don't make a very big deal out of Hallisan's dawn. Sure, we'll have a short worship service and make a sermon to encourage people to up their donations today and for the month of Hallisan, but some places make a bigger fuss. Kantoc has a lot of Hallisan worshipers and they will use any excuse to throw a jousting tournament, so a lot of districts there have a tournament in his honor. In Umera, they like to try to bundle two religious ceremonies into one so they have an observance that simultaneously honors Hallisan at the start of his Zodiac month while also honoring Korus' role in the harvest season. This is a habit the Swynfaredians and grey elves picked up too." -Sister Ragani, Fumayan gnome priestess