In large part, this calendar continued unchanged under the Roman Empire. (Egyptians used the related Alexandrian calendar, which Augustus had adapted from their wandering ancient calendar to maintain its alignment with Rome's.) A few emperors altered the names of the months after themselves or their family, but such changes were abandoned by their successors. Diocletian began the 15-year indiction cycles beginning from the AD 297 census; these became the required format for official dating under Justinian. Constantine formally established the 7-day week by making Sunday an official holiday in 321. Consular dating became obsolete following the abandonment of appointing nonimperial consuls in AD 541. The Roman method of numbering the days of the month never became widespread in the Hellenized eastern provinces and was eventually abandoned by the Byzantine Empire in its calendar.
In large part this calendar continued unchanged under the Roman Empire. (Egyptians used the related Alexandrian calendar, which Augustus had adapted from their wandering ancient calendar to ,maintain its alignment with Rome's.) A few emperors altered the names of the months after themselves or their family, but such changes were abandoned by their successors Diocletian began the 15-year indiction cycles beginning from the AD 297 census; these became the required format for official dating under Justinian. Constantine formally established the 7-day week by making Sunday .an official holiday in 321. Consular dating became obsolete following the abandonment of appointing nonimperial consuls in AD 541. The Roman method of numbering the days of the month never became widespread in the Hellenized eastern provinces and was eventually abandoned by the Byzantine Empire in its calendar.