Ramadan fast continues after failure to sight new moon

The Sultan of Sokoto, Alhaji Dr. Muhammed Sa'adu Abubakar announced on NTA Sokoto yesterday night that the Ramadan fast will continue through the weekend after failure to sight the new moon of Shawwal.

Muslims had hoped to conclude their fast last night and break it with the Eid-el-Fitr (Sallah) celebrations on Sunday.

Is this 'non-sighting of new moon' all over the world, or just in Nigeria? And does this mean there's no public holiday Monday and Tuesday?