Plan the school year in one Google Sheet. Push to two Google Calendars (public for parents, staff-only for the rest). A 🔒 prefix on a cell routes it to the Staff calendar; everything else goes public by default. One click re-syncs both.
School leaders planning the year's parent-facing and staff-facing calendars.
Needs an account that allows Apps Script authorization. First run shows a normal "unverified app" permission screen — click Advanced → Go to to proceed.