| Values for Old Faithful Area | 1991-08-31 |
|---|---|
| Astronomical Twilight Begin | 05:00 |
| Nautical Twilight Begin | 05:38 |
| Civil Twilight Begin | 06:14 |
| Sunrise | 06:44 |
| Sunset | 20:02 |
| Civil Twilight End | 20:32 |
| Nautical Twilight End | 21:08 |
| Astronomical Twilight End | 21:47 |
| Moon Illumination | 66.67% |