PUSD accidentally made the calendar of Christian* and Jewish holidays public about a year ago. I emailed them and asked why I should care, they said it was an accident. The calendar is an internal document and it is designed to help teachers with scheduling, so they don’t schedule tests or field trips on religious holidays. I received no reply when I asked about the omission of Islamic holidays.
* Some Christian churches established on the territory of Eastern Roman Empire never accepted 1582 papal bull and they never switched to Gregorian calendar. If you are Russian Orthodox your church is observing holidays based on Julian calendar. Your Christmas is on 12/25, but your calendar does not align with Gregorian, so based on the ‘western’ calendar you are observing Christmas on 1/7.