| Values for Old Faithful Area | 1931-08-21 |
|---|---|
| Astronomical Twilight Begin | 03:42 |
| Nautical Twilight Begin | 04:23 |
| Civil Twilight Begin | 05:01 |
| Sunrise | 05:32 |
| Sunset | 19:20 |
| Civil Twilight End | 19:51 |
| Nautical Twilight End | 20:29 |
| Astronomical Twilight End | 21:10 |
| Moon Illumination | 58.88% |