| Geyser | 1999-01-31 |
|---|---|
| Great Fountain | 0323 E, 1208 E, 2338 E |
| Values for Old Faithful Area | 1999-01-31 |
|---|---|
| Astronomical Twilight Begin | 06:02 |
| Nautical Twilight Begin | 06:37 |
| Civil Twilight Begin | 07:11 |
| Sunrise | 07:42 |
| Sunset | 17:30 |
| Civil Twilight End | 18:01 |
| Nautical Twilight End | 18:36 |
| Astronomical Twilight End | 19:10 |
| Moon Illumination | 99.82% |