| Geyser | 1999-12-22 |
|---|---|
| Grand | 1002 E, 2220 E |
| Great Fountain | 0434 E, 1259 E |
| Values for Old Faithful Area | 1999-12-22 |
|---|---|
| Astronomical Twilight Begin | 06:11 |
| Nautical Twilight Begin | 06:46 |
| Civil Twilight Begin | 07:23 |
| Sunrise | 07:56 |
| Sunset | 16:46 |
| Civil Twilight End | 17:20 |
| Nautical Twilight End | 17:57 |
| Astronomical Twilight End | 18:32 |
| Moon Illumination | 99.69% |