Anno Mundi
Calendar era based on biblical creation, used in Jewish and Byzantine traditions.
Wikipedia / Wikimedia Commons
Anno Mundi (Latin for 'in the year of the world'; abbreviated AM or A.M.) is a calendar era based on biblical accounts of the creation of the world and subsequent history. Two notable such eras are the Hebrew calendar, used within Jewish communities and as an official calendar in Israel, and the Creation Era of Constantinople, observed by Christian communities in the Eastern Roman Empire and retained by Eastern Orthodoxy until 1728.
- type
- Calendar era
- based_on
- Biblical accounts of creation
- Hebrew_calendar_epoch
- Sunset on 6 October 3761 BCE (proleptic Julian)
- Byzantine_calendar_epoch
- 1 September 5509 BC to 31 August 5508 BC
- difference_between_eras
- Approximately 1,732 years
- primary_texts_used
- Hebrew Masoretic Text (Hebrew calendar); Septuagint (Byzantine calendar)
Lore & Background
The Hebrew calendar's Anno Mundi count, based on rabbinic calculations from the Masoretic Text, sets creation at 3761 BCE. Its epoch corresponds to sunset on 6 October 3761 BCE (proleptic Julian). The new year begins at Rosh Hashanah in Tishrei. Anno Mundi 5786 began at sunset on 2 October 2025 (Gregorian). The calendar was formalized by Maimonides in 1178 CE, who in the Mishneh Torah set the creation date as the epoch of the Anno Mundi era.
Reader's Guide
Anno Mundi serves as a foundational chronological framework for both Jewish and Christian traditions, reflecting divergent interpretations of biblical texts. The Hebrew calendar's Anno Mundi remains central to Jewish religious life and is one of two official calendars in Israel. The Byzantine calendar's Anno Mundi, based on the Septuagint, was historically significant in Eastern Christianity until the 18th century. The discrepancy between the two eras highlights the textual variations between the Masoretic Text and the Septuagint, particularly in genealogical ages. The adoption of Anno Mundi dating by Jewish communities replaced earlier Seleucid era dating, marking a shift in calendrical practice. The era's continued use demonstrates the enduring influence of biblical chronology on historical timekeeping.
Did You Know?
- The Hebrew calendar's epoch is equivalent to sunset on 6 October 3761 BCE (proleptic Julian).
- The Byzantine calendar's Year One was 1 September 5509 BC to 31 August 5508 BC.
- The 1,732-year difference between the Hebrew and Byzantine eras is 85% due to genealogical discrepancies in Genesis.
- Maimonides formalized the Hebrew Anno Mundi era in 1178 CE in the Mishneh Torah.
Frequently Asked Questions
What is Anno Mundi?
Anno Mundi is a Latin phrase meaning 'in the year of the world,' and it refers to a method of counting years that begins with the creation event described in Genesis. Instead of anchoring time to a king's accession or an astronomical cycle, it treats the moment God spoke the cosmos into being as year one.
Which two major Anno Mundi calendar eras are still recognized?
The Hebrew calendar, which remains a living tradition in Jewish communities and an official calendar in Israel, and the Byzantine (Constantinople) Creation Era, which was used throughout the Eastern Roman Empire and was retained by Eastern Orthodox communities until 1728.
Why do the Hebrew and Byzantine Anno Mundi calendars differ by so many years?
The roughly 1,732-year gap between the two epochs comes down to the different biblical source texts each tradition relied on: the Hebrew calendar follows the Masoretic Text, while the Byzantine calendar is built on the Septuagint's chronology. Because those two versions assign different lengths to the patriarchal and exilic periods, the calculated creation date shifts accordingly.
When does year one of the Anno Mundi era begin in each tradition?
In the Hebrew calendar, year one starts at sunset on 6 October 3761 BCE (expressed in the proleptic Julian reckoning). In the Byzantine system, the first year runs from 1 September 5509 BC through 31 August 5508 BC.
Why does Anno Mundi matter to communities that follow the Genesis narrative?
It embeds the entire human timeline inside a divinely ordered sequence that begins with creation, so every historical event is read as a chapter in a story God started. For those who still observe these calendars, the Genesis account stays woven into the rhythm of daily life rather than being treated as a distant myth.
More in Genesis creation narrative 1-24
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