| Geyser | 1999-10-24 |
|---|---|
| Grand | 0914 E, 1929 E |
| Great Fountain | 0122 E, 1101 E, 2216 E |
| Values for Old Faithful Area | 1999-10-24 |
|---|---|
| Astronomical Twilight Begin | 06:12 |
| Nautical Twilight Begin | 06:46 |
| Civil Twilight Begin | 07:20 |
| Sunrise | 07:49 |
| Sunset | 18:25 |
| Civil Twilight End | 18:54 |
| Nautical Twilight End | 19:28 |
| Astronomical Twilight End | 20:02 |
| Moon Illumination | 99.43% |