proleptic Gregorian calendar (Q471)
extension of the Gregorian calendar before its introduction
| Language | Label | Description | Also known as |
|---|---|---|---|
| English | proleptic Gregorian calendar |
extension of the Gregorian calendar before its introduction |
| Language | Label | Description | Also known as |
|---|---|---|---|
| English | proleptic Gregorian calendar |
extension of the Gregorian calendar before its introduction |