//"agreed upon" is interesting, all fairy tales will come alive?//
Interestingly, “agreed upon” is the guidance coming straight from the Quran. Why do you not want to invoke the ‘mutual consultation’ provision of 42:38 if the streaks are not visible, or if you are unable to tell day from night?
About the righteous...
42:38 They respond to their Lord by establishing Salaat, AND CONDUCT THEIR AFFAIRS BY MUTUAL CONSULTATION, and they keep open for the welfare of others what We have given them. [Establishing Salaat = Establishing the System where following of the Divine Commands is facilitated. Nafaq = Open-ended tunnel = No hoarding]
Allah verily knows our mentality…
42:14 AND THEY BECAME SECTS FOR NO REASON BUT THROUGH RIVALRY AMONG THEMSELVES, After The Knowledge Had Come To Them. Had it not been for a Word that had already gone forth from your Lord for an appointed term, all matters would have been decided among them at once. The later generations who inherited the Scripture of the old still keep harboring doubts about it. [The Word = The Law of Free will = The Law of Respite]
2:187 sums it up succinctly, “Thus God explains His commands to mankind clearly, so that they understand and remain observant.”
With that, there should remain no doubt on how we set up the Saum start/end timings in such situations/regions.
2:187 ('Saum' is only for the daytime.) It is lawful for you to go to your wives on the night of the 'Saum'. They are your garments and you are their garments - close to each other, source of mutual comfort, complementing each other, trustworthy and keepers of privacy, reason for décor, and re-dressers of faults. God knows that you would have deprived yourselves like ascetics, feeling guilty, and so He turns to you and pardons you (for your ascetic thoughts). So, you may have intimate relations with them. Seek all the good that God has ordained for you. Eat and drink until you can discern the white streak of dawn against the black streak of night. Then complete the 'Saum' till the night appears. Do not have intimate relations with them while on special assignments in the Centers of the Divine System. These are the boundaries set by God - so come not near violating them. THUS GOD EXPLAINS HIS COMMANDS TO MANKIND CLEARLY, SO THAT THEY UNDERSTAND AND REMAIN OBSERVANT.
[I'tikaaf = Special task = To be deputed = Extra duty = Unique assignment. 'Aakifoon = Those on I'tikaaf. Unfortunately, under the Ajami (alien) influences, the concept given to I'tikaaf has reduced this Sublime Ordinance to ten days of ascetic and
ritualistic isolation in a mosque in the third part of Ramadhan. Obviously, this invented practice violates the Qur'anic injunctions against monasticism and human rights. (57:27). Libaas = Garment = Raiment embraces all the meanings rendered. 'Saum' or Abstinence 2:183]