| Geyser | 1999-04-15 |
|---|---|
| Great Fountain | 0058 E, 1033 E, 2043 E |
| Values for Old Faithful Area | 1999-04-15 |
|---|---|
| Astronomical Twilight Begin | 04:53 |
| Nautical Twilight Begin | 05:32 |
| Civil Twilight Begin | 06:09 |
| Sunrise | 06:39 |
| Sunset | 20:07 |
| Civil Twilight End | 20:37 |
| Nautical Twilight End | 21:14 |
| Astronomical Twilight End | 21:53 |
| Moon Illumination | 1.28% |