When sleep is a good way to boost the defences against infections [0], motivating people to stay up until midnight might not be the best idea. Perhaps change the update time to an earlier hour.
i guess there's always someone on the other side of the globe. So a reasonable time for where the majority of your audience is is the best. Unless you wanna go all out and make it timezones dependent.
That's what midnight UTC is in my timezone (US Central).