Are the position of Moon and the Sun signs in the heavens? Does the position of stars in the background of the solar bodies locate the solar system bodies, like a clock turning past the markings of its face?
I’m just saying that for the fixing of dates such as the Passover the Hebrews used a lunar calendar. The issues with the heavenlies being out of sync with a 360 day calendar were well known even in Moses’ day. So they noted the positions of the sun and moon in relation to other bodies and they used that to fix their Passover and other festivals and made adjustments to their 360 day calendar when things got too out of whack. I’m sure you know that they don’t have their festivals at the exact same dates each year but they have them around the same times...based on a lunar system.
So I understand what God gave the lights of the day and night for, so that we could plan our lives around regular scheduals and live orderly lives. He also by means of the heavenlies, declares His glory!(which is the most important reason of all)
My biggest issue is that Revelation 12 is describing the final 3.5 years of the tribulation, not the beginning. If the notion that September 23 2017 marks the sign of the Woman as per Revelation 12, the we should have already been in the middle of the tribulation period already with 3.5 years to go, watching the effects of Michael throwing Satan onto the Earth and locking him down here! Where is the Beast? Have the Northern powers attacked Israel yet per Ezekiel 38?