| Millennium: | 1st Millennium |
|---|---|
| Centuries: | 6th cent. – 7th cent. – 8th cent. |
| Decades: | 590s 600s 610s – 620s – 630s 640s 650s |
| Years: | 620 621 622 – 623 – 624 625 626 |
| Gregorian calendar | 623 DCXXIII |
| Ab urbe condita | 1376 |
| Armenian calendar | 72 ԹՎ ՀԲ |
| Assyrian calendar | 5373 |
| Bengali calendar | 30 |
| Berber calendar | 1573 |
| Buddhist calendar | 1167 |
| Burmese calendar | −15 |
| Byzantine calendar | 6131–6132 |
| Chinese calendar | 壬午年 (Water Horse) 3319 or 3259 — to — 癸未年 (Water Goat) 3320 or 3260 |
| Coptic calendar | 339–340 |
| Discordian calendar | 1789 |
| Ethiopian calendar | 615–616 |
| Hebrew calendar | 4383–4384 |
| Hindu calendars | |
| - Vikram Samvat | 679–680 |
| - Shaka Samvat | 544–545 |
| - Kali Yuga | 3723–3724 |
| Holocene calendar | 10623 |
| Iranian calendar | 1–2 |
| Islamic calendar | 1–2 |
| Japanese calendar | N/A |
| Javanese calendar | 513–514 |
| Julian calendar | 623 DCXXIII |
| Korean calendar | 2956 |
| Minguo calendar | 1289 before ROC 民前1289年 |
| Nanakshahi calendar | −845 |
| Seleucid era | 934/935 AG |
| Thai solar calendar | 1165–1166 |
The year 623 BC