Dionysius Exiguus

Hierarch

Commemorated September 1

Our father among the saints Dionysius Exiguus , also Dennis the Small , Dennis the Little or Dennis the Short - meaning humble, was a monastic theologian and canonist of the sixth century. An accomplished mathematician and astronomer, he is considered the inventor of the Christian calendar. His feast day is September 1 .

Source: OrthodoxWiki