Question

Why does gregorian calendar count days from the birth of jesus christ

Answer 1

The answer is apparently twofold: first, the calendar spread around the world with Christian colonization; second, as international trade increased, it became convenient for everyone to use the same calendar.

Answer 2

Answer:

It starts at the (approximate) date of His birth. Most biblical scholars and Bible history timelines have organized all of the biblical events in order to more accurately date the life of Jesus and history of the early church and concluded that the earlier estimates were off by a few years. Most now date His birth at 4–5 BCE (BC) and His death at 29–30 CE (AD).