| Geyser | 1999-04-17 |
|---|---|
| Great Fountain | 0403 E, 1638 E |
| Values for Old Faithful Area | 1999-04-17 |
|---|---|
| Astronomical Twilight Begin | 04:48 |
| Nautical Twilight Begin | 05:28 |
| Civil Twilight Begin | 06:05 |
| Sunrise | 06:35 |
| Sunset | 20:09 |
| Civil Twilight End | 20:40 |
| Nautical Twilight End | 21:17 |
| Astronomical Twilight End | 21:56 |
| Moon Illumination | 1.74% |