There is nothing absolutely certain.

This is the view of the majority of scholars, and some have even reported consensus.

That the death of the Prophet ﷺ was on the twelfth of Rabi' al-Awwal, this is almost agreed upon.

That is, the death of the Prophet, the twelfth of Rabi' al-Awwal. The birth of the Prophet is a matter of disagreement.

There are five opinions, the most well-known is that it was on the twelfth.

While it is agreed that it was on a Monday, which Monday is not known. The most common view is that it was on the twelfth of Rabi' al-Awwal, but there are five opinions.

But as for his death, there is almost unanimous agreement that it was indeed on the twelfth of Rabi' al-Awwal.