How do I avoid missing my match?

The website is the authoritative schedule: every tournament's page lists the round times, and its Overview tab shows which round is next and how long until it starts.

For alerts away from the site, the Creta Games mobile app sends a push when registration opens, when your match is about to start, and when results are in — signed in with the same Creta account you use here. Where the app is not yet available for your platform, the site's own countdowns are what to rely on.

Note that match times are set per round when the tournament is created, so they do not move to suit individual players. Check them before you register.