| Geyser | 1991-12-01 |
|---|---|
| Fantail | 1991-10-20 0000-1992-05-01 2359 |
| Values for Old Faithful Area | 1991-12-01 |
|---|---|
| Astronomical Twilight Begin | 05:55 |
| Nautical Twilight Begin | 06:30 |
| Civil Twilight Begin | 07:06 |
| Sunrise | 07:39 |
| Sunset | 16:45 |
| Civil Twilight End | 17:17 |
| Nautical Twilight End | 17:54 |
| Astronomical Twilight End | 18:29 |
| Moon Illumination | 22.72% |