The DOE started a high school admissions events calendar a few years ago. You can find it on the DOE website under Visit High Schools or here:
In the past, this was an incomplete source - not all high schools submitted their info to be included. Also, there were times a school submitted info to this calendar, and then changed things up and different info was posted on the school's website. This can get tricky and confusing.
I trust what’s posted on an individual school’s website over info on this calendar. The calendar can give a good sense of all that’s going on but I’d also take it with a grain of salt.