A Fast That Took Three Centuries to Reach Forty Days

Lent's forty day span, the duration this rule records counting the forty six calendar days from Ash Wednesday to Easter with Sundays excluded, was not the length of the pre Easter fast from the Church's earliest period. Sources from the second century, including a report preserved by the historian Eusebius attributed to Irenaeus, describe a much shorter fast before Easter in various communities, in some accounts as brief as a day or two, kept with real variation between different churches rather than a single fixed practice.

The forty day length that eventually became standard drew its number from two scriptural precedents rather than from any single authoritative ruling, Jesus's own forty days of fasting in the wilderness described at the start of his ministry in the Gospels, and the earlier forty day fasts attributed to Moses and Elijah in Hebrew scripture. The gradual lengthening and standardization of the fast across different regional churches took roughly the length of the early Christian centuries themselves, with the forty day form generally treated as reasonably well established by the fourth century, around the same period the Council of Nicaea was separately working to standardize the date of Easter itself.