| Geyser | 1991-10-23 |
|---|---|
| Fantail | 1991-10-20 0000-1992-05-01 2359 |
| Values for Old Faithful Area | 1991-10-23 |
|---|---|
| Astronomical Twilight Begin | 06:11 |
| Nautical Twilight Begin | 06:45 |
| Civil Twilight Begin | 07:18 |
| Sunrise | 07:48 |
| Sunset | 18:26 |
| Civil Twilight End | 18:56 |
| Nautical Twilight End | 19:30 |
| Astronomical Twilight End | 20:03 |
| Moon Illumination | 99.93% |