| Geyser | 1999-01-21 |
|---|---|
| Great Fountain | 1128 E |
| Values for Old Faithful Area | 1999-01-21 |
|---|---|
| Astronomical Twilight Begin | 06:10 |
| Nautical Twilight Begin | 06:44 |
| Civil Twilight Begin | 07:20 |
| Sunrise | 07:52 |
| Sunset | 17:16 |
| Civil Twilight End | 17:48 |
| Nautical Twilight End | 18:24 |
| Astronomical Twilight End | 18:58 |
| Moon Illumination | 14.49% |