| Values for Old Faithful Area | 1991-09-10 |
|---|---|
| Astronomical Twilight Begin | 05:15 |
| Nautical Twilight Begin | 05:51 |
| Civil Twilight Begin | 06:26 |
| Sunrise | 06:56 |
| Sunset | 19:44 |
| Civil Twilight End | 20:13 |
| Nautical Twilight End | 20:48 |
| Astronomical Twilight End | 21:25 |
| Moon Illumination | 4.19% |