| Geyser | 1991-10-31 |
|---|---|
| Fantail | 1991-10-20 0000-1992-05-01 2359 |
| Values for Old Faithful Area | 1991-10-31 |
|---|---|
| Astronomical Twilight Begin | 05:20 |
| Nautical Twilight Begin | 05:54 |
| Civil Twilight Begin | 06:29 |
| Sunrise | 06:59 |
| Sunset | 17:14 |
| Civil Twilight End | 17:44 |
| Nautical Twilight End | 18:19 |
| Astronomical Twilight End | 18:52 |
| Moon Illumination | 38.85% |