| Geyser | 1999-01-17 |
|---|---|
| Great Fountain | 0913 E, 1948 E |
| Values for Old Faithful Area | 1999-01-17 |
|---|---|
| Astronomical Twilight Begin | 06:12 |
| Nautical Twilight Begin | 06:47 |
| Civil Twilight Begin | 07:22 |
| Sunrise | 07:55 |
| Sunset | 17:11 |
| Civil Twilight End | 17:43 |
| Nautical Twilight End | 18:19 |
| Astronomical Twilight End | 18:54 |
| Moon Illumination | 0.16% |