Millennia (mil.) to Years (yr) Conversion
Millennia
A millennium is a unit of time equal to exactly 1,000 years (31,557,600,000 seconds using the Julian year). It is used in archaeology, geology, and history to describe long cultural and geological periods. The concept gained popular attention at the transition from the second to the third millennium AD (year 2000/2001). In astronomy, the precession of Earth's rotation axis completes one full cycle (the "Platonic year") in approximately 26 millennia.
Years
The year is based on Earth's orbital period around the Sun. The Julian year used in astronomy is exactly 365.25 days (31,557,600 seconds). The Gregorian calendar approximates the tropical year as 365.2425 days through its leap year rule, achieving accuracy to within 26 seconds per year. In geology, time spans are expressed in millions of years (Ma) or billions of years (Ga).
| Millennia (mil.) | Years (yr) |
|---|---|
| 0.1 mil. | 100 yr |
| 1 mil. | 1000 yr |
| 2 mil. | 2000 yr |
| 3 mil. | 3000 yr |
| 5 mil. | 5000 yr |
| 10 mil. | 10000 yr |
| 20 mil. | 20000 yr |
| 30 mil. | 30000 yr |
| 50 mil. | 50000 yr |
| 100 mil. | 100000 yr |
| 1000 mil. | 1000000 yr |