See how historical BCE years resolve to decade, century, millennium, million-year, and billion-year periods.
Choose a precision, year encoding, and historical year. The selected card shows its supplied year and expected historical range. Switching encoding changes the raw year value while preserving its historical position. To experiment with dates beyond these presets, use the Date Precision example.
The precision setting resolves any supplied year to the boundaries of its containing period. For example, 1 BCE and 9 BCE both resolve to the visible 9–1 BCE range at decade precision. The 29–20 BCE and 19–10 BCE ranges follow visible tens, while the shorter 9–1 BCE and 1–9 CE periods each contain nine years. The parent row shows the handoff across the era boundary.
The coloured period line beneath the card shows its resolved range. Changing a dropdown updates the article and fits that range. For the date rules and input numbering, see BCE numbering and parent label formatting.