Uploaded October 2018 | Updated September 2026, 2 weeks ago
This ancient mechanical calendar is the second oldest geared device ever discovered.
It included both a sundial for telling the time and a geared calendar, driven by a dial showing the seven days of the week. Although only these fragments survive, evidence suggests that it may have been used to convert between a popular calendar based on the phases of the Moon and the official Sun-based calendar of the Byzantine Empire.
See more images of this sundial calendar in our online collection
collection.sciencemuseum.org.uk/objects/co1082/byzantine-portable-universal-altitude-sundial-with-geared-calendrical-device-sundial-perpetual-calendar
See this sundial calendar in our blockbuster exhibition:
The Sun: Living With Our Star
6 October 2018 – 6 May 2019
Find out more: bit.ly/2pEeSrj
This ancient mechanical calendar is the second oldest geared device ever discovered.
It included both a sundial for telling the time and a geared calendar, driven by a dial showing the seven days of the week. Although only these fragments survive, evidence suggests that it may have been used to convert between a popular calendar based on the phases of the Moon and the official Sun-based calendar of the Byzantine Empire.
See more images of this sundial calendar in our online collection
collection.sciencemuseum.org.uk/objects/co1082/byzantine-portable-universal-altitude-sundial-with-geared-calendrical-device-sundial-perpetual-calendar
See this sundial calendar in our blockbuster exhibition:
The Sun: Living With Our Star
6 October 2018 – 6 May 2019
Find out more: bit.ly/2pEeSrj
