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 it didn’t. This definition applies to all Gregorian calendar countries. There is no century number, you go from -1 to 1. If you disagree with this, please write your complaint to: Pope, Cathedral of Saint-Peter of Roma, Vatican.

Literal translation:

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

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.