| Values for Old Faithful Area | 1931-08-20 |
|---|---|
| Astronomical Twilight Begin | 03:40 |
| Nautical Twilight Begin | 04:22 |
| Civil Twilight Begin | 05:00 |
| Sunrise | 05:31 |
| Sunset | 19:22 |
| Civil Twilight End | 19:53 |
| Nautical Twilight End | 20:31 |
| Astronomical Twilight End | 21:12 |
| Moon Illumination | 47.95% |