Your guidance regarding the disagreement over the basis for determining the start and end of the month of Ramadan?

Question:
A questioner says: One of the causes of disagreement among Muslim communities in Western countries is the disagreement over the basis for determining the start and end of the month of Ramadan. We hope for your Eminence’s guidance in this matter, and may Allah preserve you.

Answer:
It is obligatory to pay attention to the sighting of the moon and to completing the count. This is what the Prophet (peace and blessings be upon him) taught his Ummah: "Fast when you see it, and break your fast when you see it. If it is obscured from you, then complete the count." You may not enter Ramadan by praying one or two days early.
You may not enter Ramadan until you see the crescent moon or the count is completed, and you do not break your fast until you see the crescent moon or the count is completed. So, do not fast until you see the crescent moon or the count is completed, and do not break your fast unless it is so. This is the obligation: either by the sighting of the crescent moon of Ramadan, or by completing the count of Sha'ban. And so it is with fasting: one fasts thirty days until he sees the crescent moon of Shawwal, or completes thirty days, except if Shawwal follows the thirty days of Sha'ban, in which case fasting twenty-nine days is permissible. The point is to complete the count, unless the crescent moon is sighted for fasting or breaking the fast. As for calculations, they are not relied upon. Calculations are not relied upon; rather, it is by the sighting or by completing the count. This is how the Sunnah came from the Messenger of Allah (peace and blessings be upon him). It is obligatory for all Islamic countries to pay attention to this. If they do not see the crescent moon, they rely on the sighting of one who saw it with proof, and praise be to Allah. Yes.