Free Tool
Discord Weekly Schedule Generator
List your recurring events with a weekday, time and timezone, and get a schedule message that uses <t:...:t> for the next occurrence of each one. Discord renders every timestamp in the reader's own timezone, so one message works for the whole server.
Each <t:> tag points at one specific moment (the next occurrence as of when you generate this), not a repeating rule. Regenerate and re-post weekly, or use the "short time only" style so the message keeps reading correctly as long as your event times do not change. For one-off dates use the timestamp generator; to run the events themselves, see the rosters docs.