| Geyser | 1999-04-04 |
|---|---|
| Great Fountain | 0458 E, 1548 E |
| Values for Old Faithful Area | 1999-04-04 |
|---|---|
| Astronomical Twilight Begin | 05:17 |
| Nautical Twilight Begin | 05:54 |
| Civil Twilight Begin | 06:29 |
| Sunrise | 06:58 |
| Sunset | 19:53 |
| Civil Twilight End | 20:23 |
| Nautical Twilight End | 20:58 |
| Astronomical Twilight End | 21:35 |
| Moon Illumination | 89.91% |