Module implementing the Wikisource-specific categorisation of years into literary "eras": Ancient, Medieval, Renaissance, Early modern, Modern, and Future. Its main user-accessible client is {{What era is}}, but the main use is for {{Author}} (through Module:Author) and its automatically added categories (the subcategories of Category:Authors by era).

The named eras represent years as follows:

Era Years
Ancient Before 600
Medieval 601–1420
Renaissance 1421–1630
Early modern 1631–1900
Modern 1901–2024
Future 2025–

From template code the function is called with {{#invoke:Era|main}} and the year parameter is extracted from the calling frame (the arguments given to the template). See {{What era is}} for an example. From a wikipage the year can be provided directly in the invocation: {{#invoke:Era|main|1623}} → Renaissance.

From a Lua module there is a simplified (and nominally faster) calling convention that avoids the need for having a frame object or checking the parent frame. After loading the module (local e = require Module:Era) you can call its .era() function with a year as the only parameter: local era = e.era(1623).

However called the return value is always a plain string with no markup or styling.