How many hours (maximum) can an eagle fly in the sky at a time?

The best answer I can find to this is that the Bald Eagle (note: the question doesn't specify the species of eagle) flies from sun-up to sun-down when migrating in the winter to find unfrozen, open water to catch its meals from (stated in the link from 8 AM to 6 PM = 10 hours using thermal currents and its body enabled soaring ability). ................. https://en.wikipedia.org/wiki/Bald_eagle