| Millennium: | 2nd millennium |
|---|---|
| Centuries: | |
| Decades: | |
| Years: |
| 1603 by topic |
|---|
| Arts and science |
| Leaders |
| Birth and death categories |
| Births – Deaths |
| Establishments and disestablishments categories |
| Establishments – Disestablishments |
| Works category |
| Gregorian calendar | 1603 MDCIII |
| Ab urbe condita | 2356 |
| Armenian calendar | 1052 ԹՎ ՌԾԲ |
| Assyrian calendar | 6353 |
| Balinese saka calendar | 1524–1525 |
| Bengali calendar | 1010 |
| Berber calendar | 2553 |
| English Regnal year | 45 Eliz. 1 – 1 Ja. 1 |
| Buddhist calendar | 2147 |
| Burmese calendar | 965 |
| Byzantine calendar | 7111–7112 |
| Chinese calendar | 壬寅年 (Water Tiger) 4300 or 4093 — to — 癸卯年 (Water Rabbit) 4301 or 4094 |
| Coptic calendar | 1319–1320 |
| Discordian calendar | 2769 |
| Ethiopian calendar | 1595–1596 |
| Hebrew calendar | 5363–5364 |
| Hindu calendars | |
| - Vikram Samvat | 1659–1660 |
| - Shaka Samvat | 1524–1525 |
| - Kali Yuga | 4703–4704 |
| Holocene calendar | 11603 |
| Igbo calendar | 603–604 |
| Iranian calendar | 981–982 |
| Islamic calendar | 1011–1012 |
| Japanese calendar | Keichō 8 (慶長８年) |
| Javanese calendar | 1523–1524 |
| Julian calendar | Gregorian minus 10 days |
| Korean calendar | 3936 |
| Minguo calendar | 309 before ROC 民前309年 |
| Nanakshahi calendar | 135 |
| Thai solar calendar | 2145–2146 |
| Tibetan calendar | 阳水虎年 (male Water-Tiger) 1729 or 1348 or 576 — to — 阴水兔年 (female Water-Rabbit) 1730 or 1349 or 577 |
1603 (MDCIII) was a common year starting on Wednesday of the Gregorian calendar and a common year starting on Saturday of the Julian calendar, the 1603rd year of the Common Era (CE) and Anno Domini (AD) designations, the 603rd year of the 2nd millennium, the 3rd year of the 17th century, and the 4th year of the 1600s decade. As of the start of 1603, the Gregorian calendar was 10 days ahead of the Julian calendar, which remained in localized use until 1923.