Assalamu Alaikum Wa Rahmatullah
How did Islam calculate time back when it came about?
بسم الله الرحمن الرحيم
In the name of Allah, the Most Gracious, the Most Merciful.
Allah says in the Quran “Indeed, the number of months with Allah is twelve [lunar] months in the register of Allah [from] the day He created the heavens and the earth; of these, four are sacred…”
The Islamic calendar follows the lunar calendar, which means that a month is either 29 or 30 days -as the Prophet (peace be upon him) has explicitly mentioned in another hadith- according to when the moon is sighted.
Only Allah SWT alone knows best.
Answered by Maulana Imran Mughal
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham