| Geyser | 1999-12-11 |
|---|---|
| Grand | 0308 E, 1444 E |
| Great Fountain | 0154 E, 1243 E |
| Values for Old Faithful Area | 1999-12-11 |
|---|---|
| Astronomical Twilight Begin | 06:04 |
| Nautical Twilight Begin | 06:39 |
| Civil Twilight Begin | 07:16 |
| Sunrise | 07:49 |
| Sunset | 16:43 |
| Civil Twilight End | 17:16 |
| Nautical Twilight End | 17:53 |
| Astronomical Twilight End | 18:28 |
| Moon Illumination | 9.71% |