| Geyser | 1999-05-18 |
|---|---|
| Great Fountain | 0728 E, 1758 E |
| Values for Old Faithful Area | 1999-05-18 |
|---|---|
| Astronomical Twilight Begin | 03:43 |
| Nautical Twilight Begin | 04:35 |
| Civil Twilight Begin | 05:18 |
| Sunrise | 05:52 |
| Sunset | 20:46 |
| Civil Twilight End | 21:20 |
| Nautical Twilight End | 22:04 |
| Astronomical Twilight End | 22:55 |
| Moon Illumination | 11.03% |