| Geyser | 1999-03-31 |
|---|---|
| Great Fountain | 0253 E, 1243 E, 2228 E |
| Values for Old Faithful Area | 1999-03-31 |
|---|---|
| Astronomical Twilight Begin | 04:25 |
| Nautical Twilight Begin | 05:02 |
| Civil Twilight Begin | 05:36 |
| Sunrise | 06:06 |
| Sunset | 18:48 |
| Civil Twilight End | 19:18 |
| Nautical Twilight End | 19:52 |
| Astronomical Twilight End | 20:29 |
| Moon Illumination | 99.59% |