Just as no one knows when the Hour will come, no one knows when its signs will appear. Reports claiming that such-and-such will occur in one year and such-and-such will happen in another are inauthentic. The Hijri calendar was not instituted during the Prophet’s lifetime, peace and blessings be upon him. Rather, Umar ibn al-Khattāb, may Allah be pleased with him, instituted it as an exercise of independent judgment and made the Prophet’s migration to Medina its starting point.

Al-Qurtubī said: “What the Prophet, peace and blessings be upon him, foretold concerning tribulations and future events will indeed occur. However, assigning them to a particular year requires an authentic chain of transmission that establishes the matter conclusively. This is like the time of the Hour: no one knows in which year or month it will occur. It will, however, take place on a Friday, during its final hour—the hour in which Allah created Adam, peace be upon him. But which Friday it will be is known only to Allah, alone without partner. Likewise, no one knows the specific times at which the signs will occur. And Allah knows best” (1).