My update starts 4:20 AM Amsterdam time. My server time follows daylight saving time (twice a year it changes one hour).
After I start my update, it takes 2 minutes to complete. However, in rare occasions of prolonged high server load, AWS throttles the CPU down to 20%. Combined with the high load, that can cause the update to take at least ten times longer. So keep some margin after the start of my cronjob

Full disclosure: during the daily update, I add lines to existing live TXT files, so if you download at "the wrong moment" right when I'm updating, you may miss out on the last lines. The compressed file doesn't have that risk.