| Geyser | 1999-04-30 |
|---|---|
| Castle | 0617 E, 2059 E |
| Great Fountain | 0318 E, 1148 E, 2148 E |
| Values for Old Faithful Area | 1999-04-30 |
|---|---|
| Astronomical Twilight Begin | 04:20 |
| Nautical Twilight Begin | 05:04 |
| Civil Twilight Begin | 05:43 |
| Sunrise | 06:15 |
| Sunset | 20:25 |
| Civil Twilight End | 20:57 |
| Nautical Twilight End | 21:37 |
| Astronomical Twilight End | 22:20 |
| Moon Illumination | 99.88% |