| Geyser | 1991-12-15 |
|---|---|
| Fantail | 1991-10-20 0000-1992-05-01 2359 |
| Values for Old Faithful Area | 1991-12-15 |
|---|---|
| Astronomical Twilight Begin | 06:07 |
| Nautical Twilight Begin | 06:42 |
| Civil Twilight Begin | 07:19 |
| Sunrise | 07:52 |
| Sunset | 16:44 |
| Civil Twilight End | 17:17 |
| Nautical Twilight End | 17:54 |
| Astronomical Twilight End | 18:29 |
| Moon Illumination | 59.06% |