Explained: The '30:30 rule' in cricket for lightning stopping play

Lightning and thunder halted play on the final morning of the rain-affected third Test between India and Australia at the Gabba. Australia quickly took the last Indian wicket, securing a 185-run lead. The ICC's 30:30 lightning rule, prioritizing safety, led to the suspension, as the match moved towards a draw on the concluding day.

source https://timesofindia.indiatimes.com/sports/cricket/india-in-australia/explained-whats-the-3030-rule-in-cricket-for-lightning-and-thunder-stopping-play/articleshow/116417768.cms