| Geyser | 1991-10-21 |
|---|---|
| Fantail | 1991-10-20 0000-1992-05-01 2359 |
| Giant | 1722 |
| Values for Old Faithful Area | 1991-10-21 |
|---|---|
| Astronomical Twilight Begin | 06:08 |
| Nautical Twilight Begin | 06:42 |
| Civil Twilight Begin | 07:16 |
| Sunrise | 07:45 |
| Sunset | 18:30 |
| Civil Twilight End | 18:59 |
| Nautical Twilight End | 19:33 |
| Astronomical Twilight End | 20:07 |
| Moon Illumination | 94.26% |