How does grafana decide when to start evaluating

Hello. We have a data source in which new data comes every hour ( between the first 30 minutes of every hour). We want to set the alerts to start evaluating after new data has come. So at the 45th minute of every new hour ( 00:45, 1:45, 2:45 …)
How to do that? On what basis does Grafana decide when to start evaluating? Is it the rule create/update time.

Current: Evaluate every 1hr for 0s
Grafana version: 9.2.2

@mattabrams Can you help please?