Two festival dates set the calendar for artist petitions
A city that hosts a March festival and an October one has two fixed points in its immigration year, and the filings that make either possible happen seasons ahead.
Bands, crews, speakers and their managers rarely think about a petition until the booking is confirmed, which is late. The firms that get those files are the ones already visible when the booking lands.
So the publishing window for March is the previous fall, and the window for the Zilker weekends is the spring. Anything posted during a festival reaches a city with no attention left and nobody in a position to act on it.
Write for the person who books rather than the person who performs. A venue on South Congress, a manager, a small promoter, a stage crew lead. They ask the same handful of questions every single year, and they ask them early.
Those weeks are also when the whole industry is in one place, which means the material you put out in the run up gets read by people sitting next to your future clients.