| Geyser | 1999-10-15 |
|---|---|
| Grand | 0735 E, 1932 E |
| Great Fountain | 0024 E, 0947 E, 2125 E |
| Values for Old Faithful Area | 1999-10-15 |
|---|---|
| Astronomical Twilight Begin | 06:01 |
| Nautical Twilight Begin | 06:35 |
| Civil Twilight Begin | 07:09 |
| Sunrise | 07:38 |
| Sunset | 18:39 |
| Civil Twilight End | 19:09 |
| Nautical Twilight End | 19:42 |
| Astronomical Twilight End | 20:16 |
| Moon Illumination | 28.22% |