Astronomical Year Numbering
calendarEmbed This Widget
Add the script tag and a data attribute to embed this widget.
<script src="https://cdn.jsdelivr.net/npm/timefyi-embed@1/dist/embed.min.js" defer></script>
<div data-timefyi="glossary" data-slug="astronomical-year-numbering"></div>Embed via iframe for maximum compatibility.
<iframe src="https://timefyi.com/iframe/glossary/astronomical-year-numbering/" width="420" height="400" frameborder="0" style="border:0;border-radius:10px;max-width:100%" loading="lazy"></iframe>Paste this URL in WordPress, Medium, or any oEmbed-compatible platform.
https://timefyi.com/glossary/astronomical-year-numbering/Add a dynamic SVG badge to your README or docs.
[](https://timefyi.com/glossary/astronomical-year-numbering/)Use the native HTML custom element.
<script src="https://cdn.jsdelivr.net/npm/timefyi-embed@1/dist/embed.min.js" defer></script>
<timefyi-glossary slug="astronomical-year-numbering"></timefyi-glossary>Definition
A year numbering system used by astronomers that includes a year zero (0 AD) and uses negative numbers for BC years. In this system, 1 BC = year 0, and 2 BC = year -1.