| Geyser | 1999-04-23 |
|---|---|
| Castle | 0350 E, 1832 E |
| Great Fountain | 0103 E, 0933 E, 1908 E |
| Values for Old Faithful Area | 1999-04-23 |
|---|---|
| Astronomical Twilight Begin | 04:35 |
| Nautical Twilight Begin | 05:16 |
| Civil Twilight Begin | 05:55 |
| Sunrise | 06:26 |
| Sunset | 20:17 |
| Civil Twilight End | 20:48 |
| Nautical Twilight End | 21:26 |
| Astronomical Twilight End | 22:07 |
| Moon Illumination | 54.84% |