Moonsighting.com has been monitoring Saudi's announcements for about two decades, and consistently their month starts earlier than any place on earth month after month. The only explanation we can find is that they use a pre-calculated calendar based on "New-moon" that is invisible. Their Official Ummul-Qura calendar of 30 years shows every month begins one day after New-moon date of Greenwich Mean time (now called Universal time).
The possibilities for Saudi's decision are:A few claims of sighting an invisible moon come and the authorities accept them saying that a pious and credible Muslim has given the witness, so it completes Shari'ah requirement.If they don't see on the 30th day, they use a justification that 30 days are completedIn fact, the moon is always visible on 30th day, if the month started on actual and authentic moonsighting. If the moon is not visible on 30th day, it means that the beginning of the month was in error either due to pre-calculated date that was not based on moonsighting or due to mistaken sighting claimsCheck out how Saudi Arabia establish their Hijri calendar.Since 1999 (1420 AH) the rule has been as follows: On the 29th day of an Islamic month, the times when the sun and the moon set are compared. If the sun sets before the moon, the next day will be the first of a new month; but if the moon sets before the sun, the next day will be the last (30th) of the current month
