| Geyser | 1991-05-20 |
|---|---|
| Whistle | 1991-05-12 0000-1991-05-24 0000 |
| Values for Old Faithful Area | 1991-05-20 |
|---|---|
| Astronomical Twilight Begin | 03:40 |
| Nautical Twilight Begin | 04:32 |
| Civil Twilight Begin | 05:16 |
| Sunrise | 05:50 |
| Sunset | 20:48 |
| Civil Twilight End | 21:23 |
| Nautical Twilight End | 22:07 |
| Astronomical Twilight End | 22:59 |
| Moon Illumination | 43.72% |