| Geyser | 1999-12-24 |
|---|---|
| Grand | 0944 E, 2056 E |
| Great Fountain | 0034 E, 1101 E, 2008 E |
| Values for Old Faithful Area | 1999-12-24 |
|---|---|
| Astronomical Twilight Begin | 06:12 |
| Nautical Twilight Begin | 06:47 |
| Civil Twilight Begin | 07:24 |
| Sunrise | 07:57 |
| Sunset | 16:47 |
| Civil Twilight End | 17:21 |
| Nautical Twilight End | 17:58 |
| Astronomical Twilight End | 18:33 |
| Moon Illumination | 96.38% |