These 'hilal' wars that go on distracts us by giving us a false sense of being 'busy' of actually 'doing something' when in reality all we are doing is fighting over things that will never agree on, until maybe when Imam Mehdi shows up.
If it REALLY mattered to people they would be monitoring the moon every month to determine the hilal, the beginning and end of Islamic month as well as getting experience instead of just paying lip service to the sunnah and creating fights under the guise of unity in the ummah.
Some people from now until the day of judgment (or until Imam Mehdi. Allahu Aalim) will fast 29 and others 30 days. Its not that big of a deal. What we can all agree on is that NO ONE will be fasting a continuous 28 day fast or a 31 since the Islamic month doesn't accommodate that.
The US Navy monitors the moon very carefully (tides and all)
Crescent Moon Visibility and the Islamic Calendar (SUBHANAALLAH, super indepth and worth a read.