| Geyser | 1999-05-23 |
|---|---|
| Great Fountain | 0203 E, 1143 E, 1953 E |
| Values for Old Faithful Area | 1999-05-23 |
|---|---|
| Astronomical Twilight Begin | 03:34 |
| Nautical Twilight Begin | 04:28 |
| Civil Twilight Begin | 05:13 |
| Sunrise | 05:47 |
| Sunset | 20:52 |
| Civil Twilight End | 21:26 |
| Nautical Twilight End | 22:11 |
| Astronomical Twilight End | 23:05 |
| Moon Illumination | 60.41% |