Zero century

A couple of lines from the PostgreSQL documentation ( section 9.9.1. EXTRACT, date_part ):

The first century starts at 0001-01-01 00:00:00 AD, although they did not know it at the time. This definition applies to all Gregorian calendar countries. There is no century number 0, you go from -1 to 1. If you disagree with this, please write your complaint to: Pope, Cathedral Saint-Peter of Roma, Vatican.

Literal translation:

The first century begins at 0001-01-01 00:00:00 AD, although then it was not yet known. This definition applies to all countries of the Gregorian calendar. There is no zero century, followed by the 1st is immediately the 1st. If you do not agree with this, please write your complaint to the following address: Pope, St. Peter's Basilica, Vatican City.

On the one hand it made me smile, on the other - an interesting fact. This is one of the few cases when the natural numbering order is violated.