Breaking fast and negligence in determining its right time

Q: The muezzin pronounced Adhan (call to Salah) for Maghrib (Sunset) Prayer at 5:37 P.M. And Madfa` Al-Iftar (the canon signaling breaking the fast time) was heard at the same time, followed by other muezzins pronouncing Adhan. The people started breaking their fast. Those muezzins thought that the time of Maghrib had already started and the sun had set, because it was cloudy, although the official time of Maghrib as set in the calendar and determined by the Department of Astronomy in the University of King Su`ud was at 5:45 P.M. Then Madfa` Al-Iftar was heard again at this time, and other muezzins pronounced Adhan, and some people started breaking their fast at that time. Your Eminence Shaykh, people are confused; some of them believe fast of that day was nullified and must be made up for due to such negligence of determining the right time, since the clock was available and they could know the exact time. Others said that we do not have to make up for this day, and the one who carries this sin and should make up for the day is the one who caused this problem. Therefore, we request Your Eminence to quickly resolve this issue, so that this problem will be settled. May Allah grant you success and guide your steps on the Straight Path.

A: If the case is as you mentioned, then they should make up for that day, because they broke their fast before (Part No. 9; Page No. 186) the due time of breaking fast and due to their negligence in determining the right time.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.