| Geyser | 1991-12-21 |
|---|---|
| Fantail | 1991-10-20 0000-1992-05-01 2359 |
| Values for Old Faithful Area | 1991-12-21 |
|---|---|
| Astronomical Twilight Begin | 06:10 |
| Nautical Twilight Begin | 06:46 |
| Civil Twilight Begin | 07:23 |
| Sunrise | 07:56 |
| Sunset | 16:46 |
| Civil Twilight End | 17:19 |
| Nautical Twilight End | 17:56 |
| Astronomical Twilight End | 18:32 |
| Moon Illumination | 99.97% |