| Geyser | 1999-01-20 |
|---|---|
| Great Fountain | 0253 E, 1153 E, 2308 E |
| Values for Old Faithful Area | 1999-01-20 |
|---|---|
| Astronomical Twilight Begin | 06:10 |
| Nautical Twilight Begin | 06:45 |
| Civil Twilight Begin | 07:21 |
| Sunrise | 07:53 |
| Sunset | 17:15 |
| Civil Twilight End | 17:47 |
| Nautical Twilight End | 18:23 |
| Astronomical Twilight End | 18:57 |
| Moon Illumination | 7.65% |