| Geyser | 1999-02-17 |
|---|---|
| Great Fountain | 0328 E, 1423 E |
| Values for Old Faithful Area | 1999-02-17 |
|---|---|
| Astronomical Twilight Begin | 05:42 |
| Nautical Twilight Begin | 06:16 |
| Civil Twilight Begin | 06:50 |
| Sunrise | 07:20 |
| Sunset | 17:54 |
| Civil Twilight End | 18:24 |
| Nautical Twilight End | 18:58 |
| Astronomical Twilight End | 19:31 |
| Moon Illumination | 1.28% |