| Values for Old Faithful Area | 1971-07-21 |
|---|---|
| Astronomical Twilight Begin | 03:45 |
| Nautical Twilight Begin | 04:38 |
| Civil Twilight Begin | 05:23 |
| Sunrise | 05:58 |
| Sunset | 21:01 |
| Civil Twilight End | 21:35 |
| Nautical Twilight End | 22:20 |
| Astronomical Twilight End | 23:13 |
| Moon Illumination | 1.42% |