The heavenly bodies are signs because natural things are parables as well as showing seasons and times. See how the sun subtends exactly the same angle as the moon and looks the same size even though the sun is much bigger. The eclipse is like it is because they overlap so closely by these angles they subtend. Then see the sign of design in nature by how we only see one side of the moon because it rotates at exactly the same angular speed as the time it takes to orbit Earth and always has done constantly in history. It shows it is created deliberately and keeps to God's design obediently. The times as God revealed them to mankind include a 364 day year and heavenly records seem to record years as 364 day years. The ancient Greeks did not like the year to not be the same as the time it takes for a natural year to complete but they did not change the year to 365.25 days. The Romans did follow Greek astronomer and Roman astronomer advice about the natural year length being :365.25 days long and they changed it under Julius Caesar's leadership and he made a new calendar on advice of these astronomers including a month named after himself and making sure this month July was one of the longest. Augustus changed it again and got himself a month named after him and changed February to decrease it so his month August could be just as long as July. The calendar stayed like this up until the time when popes ruled the empire and astronomers found the year was slightly too short and it made feast days less and less accurate so they persuaded Pope Gregory to change it again. Gradually the whole world came to switch to this Roman Empire calendar. Some countries only switched in the last couple of centuries. Heaven probably still uses the calendar they always used and taught to humans as recorded in the Book of Enoch - 364 days long. The Hebrew calendar included in the Law is similar to the Enochian calendar because it combines solar and lunar.
