| Millennium: | 1st millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 804 by topic |
|---|
| Leaders |
| Categories |
| Gregorian calendar | 804 DCCCIV |
| Ab urbe condita | 1557 |
| Armenian calendar | 253 ԹՎ ՄԾԳ |
| Assyrian calendar | 5554 |
| Balinese saka calendar | 725–726 |
| Bengali calendar | 211 |
| Berber calendar | 1754 |
| Buddhist calendar | 1348 |
| Burmese calendar | 166 |
| Byzantine calendar | 6312–6313 |
| Chinese calendar | 癸未年 (Water Goat) 3501 or 3294 — to — 甲申年 (Wood Monkey) 3502 or 3295 |
| Coptic calendar | 520–521 |
| Discordian calendar | 1970 |
| Ethiopian calendar | 796–797 |
| Hebrew calendar | 4564–4565 |
| Hindu calendars | |
| - Vikram Samvat | 860–861 |
| - Shaka Samvat | 725–726 |
| - Kali Yuga | 3904–3905 |
| Holocene calendar | 10804 |
| Iranian calendar | 182–183 |
| Islamic calendar | 188–189 |
| Japanese calendar | Enryaku 23 (延暦２３年) |
| Javanese calendar | 699–700 |
| Julian calendar | 804 DCCCIV |
| Korean calendar | 3137 |
| Minguo calendar | 1108 before ROC 民前1108年 |
| Nanakshahi calendar | −664 |
| Seleucid era | 1115/1116 AG |
| Thai solar calendar | 1346–1347 |
| Tibetan calendar | 阴水羊年 (female Water-Goat) 930 or 549 or −223 — to — 阳木猴年 (male Wood-Monkey) 931 or 550 or −222 |
Year 804 (DCCCIV) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar.