| Geyser | 1991-12-13 |
|---|---|
| Fantail | 1991-10-20 0000-1992-05-01 2359 |
| Values for Old Faithful Area | 1991-12-13 |
|---|---|
| Astronomical Twilight Begin | 06:05 |
| Nautical Twilight Begin | 06:41 |
| Civil Twilight Begin | 07:17 |
| Sunrise | 07:51 |
| Sunset | 16:43 |
| Civil Twilight End | 17:17 |
| Nautical Twilight End | 17:53 |
| Astronomical Twilight End | 18:29 |
| Moon Illumination | 39.47% |