Spanish era
The Spanish era (), sometimes called the era of Caesar, was a calendar era (year numbering system) commonly used in the states of the Iberian Peninsula from the 5th century until the 15th, when it was phased out in favour of the "Anno Domini" (AD) system. The epoch (start date) of the Spanish era was 1 January 38 BC. To convert an "Anno Domini" date to the corresponding year in the Spanish era, add 38 to the "Anno Domini" year, such that Era 941 would be equivalent to AD 903. A date given in the Spanish era always uses the word "era" followed by a feminine ordinal number (when written out instead of given in Roman numerals). This contrasts with the AD system that uses the masculine "anno" (year): i.e., "era millesima octava" versus "anno millesimo octavo".