| Geyser | 1999-02-18 |
|---|---|
| Great Fountain | 0138 E, 1353 E, 2303 E |
| Values for Old Faithful Area | 1999-02-18 |
|---|---|
| Astronomical Twilight Begin | 05:41 |
| Nautical Twilight Begin | 06:15 |
| Civil Twilight Begin | 06:49 |
| Sunrise | 07:18 |
| Sunset | 17:55 |
| Civil Twilight End | 18:25 |
| Nautical Twilight End | 18:59 |
| Astronomical Twilight End | 19:33 |
| Moon Illumination | 5.11% |