Rules for Spawning VIP Chest

Try as I might, I can’t seem to get a daily VIP Chest to spawn. Best I can do is about 3 in 5 days.
What are the rules for getting a VIP Chest to spawn with the minimum turn-around time to the next 1? Is it actually possible to string 7 of these together in 1 week?

I’m fairly sure it’s every 6 chests. So to get it daily you have to open chests every 4 hours as soon as they spawn. Sleeping obviously makes that difficult.