I'd appreciate any evidence of the Greeks observing anything other than only a flat earth with a circus canopy of stars atop - this is infact what Christianity took on board till the telescope was discovered. Islam is not in the loop - it is a new belief system, its scriptures upholding a flat earth, with 90% of ts scriptures being a lift off from the Hebrew and Christian bibles; Arabic itself is a new writings emerging as recently as 300 CE.
When examing the workings of the Hebrew calendar, which is unquely based on the solar, lunar and earth movements, there is no other understanding than of a sphearical earth.
Edited by IamJoseph, : No reason given.