I am currently in XYZ, and because there is no agreed-upon timetable for prayer, I have no choice but to check the prayer timetables issued by more than one organization. I rejected the timetable that goes against the consensus of the other timetables. What I mean by that is that the timetable of one of the organizations shows the time for the Fajr adhaan after 3 a.m., whilst according to many other organizations, the time for the Fajr adhaan is before 3 a.m. Because the issue has to do with fasting, I decided to err on the side of caution and follow the timetable of those organizations who say that the time is earlier. In addition to that, I try to be cautious with regard to the time for Maghrib, and I found that the organization whose timetable I decided not to follow with regard to Fajr shows the time of Maghrib to be a little later than other organizations. Hence, in order to err on the side of caution, I will follow it [with regard to Maghrib], in sha Allah.
My question is: is what I did of adopting a cautious approach valid? More importantly, if I follow the earlier time for the Fajr adhaan, can I pray Fajr at that time, or should I wait until the time given by the other organizations? Please note that if I wait, I will be in a state of doubt and confusion, namely: how can I adopt two times for Fajr, one to start the fast and the other for the prayer? I feel that starting to fast at the earlier time, before the time of Fajr according to the other organizations, is somewhat wrong, meaning that I may reach the conclusion that it is not permissible to start fasting before the time that I have adopted for the prayer begins.