| Geyser | 1991-05-12 |
|---|---|
| Whistle | 0000-1991-05-24 0000 |
| Values for Old Faithful Area | 1991-05-12 |
|---|---|
| Astronomical Twilight Begin | 03:55 |
| Nautical Twilight Begin | 04:43 |
| Civil Twilight Begin | 05:25 |
| Sunrise | 05:59 |
| Sunset | 20:40 |
| Civil Twilight End | 21:13 |
| Nautical Twilight End | 21:55 |
| Astronomical Twilight End | 22:43 |
| Moon Illumination | 5.31% |