| Geyser | 1999-04-10 |
|---|---|
| Great Fountain | 0153 E, 1218 E |
| Values for Old Faithful Area | 1999-04-10 |
|---|---|
| Astronomical Twilight Begin | 05:04 |
| Nautical Twilight Begin | 05:42 |
| Civil Twilight Begin | 06:18 |
| Sunrise | 06:48 |
| Sunset | 20:01 |
| Civil Twilight End | 20:31 |
| Nautical Twilight End | 21:07 |
| Astronomical Twilight End | 21:45 |
| Moon Illumination | 38.79% |