| Values for Old Faithful Area | 1997-04-21 |
|---|---|
| Astronomical Twilight Begin | 04:38 |
| Nautical Twilight Begin | 05:19 |
| Civil Twilight Begin | 05:57 |
| Sunrise | 06:28 |
| Sunset | 20:15 |
| Civil Twilight End | 20:46 |
| Nautical Twilight End | 21:24 |
| Astronomical Twilight End | 22:04 |
| Moon Illumination | 97.45% |