| Values for Old Faithful Area | 1977-09-01 |
|---|---|
| Astronomical Twilight Begin | 05:02 |
| Nautical Twilight Begin | 05:40 |
| Civil Twilight Begin | 06:16 |
| Sunrise | 06:46 |
| Sunset | 20:00 |
| Civil Twilight End | 20:30 |
| Nautical Twilight End | 21:06 |
| Astronomical Twilight End | 21:44 |
| Moon Illumination | 87.4% |