| Values for Old Faithful Area | 1973-07-31 |
|---|---|
| Astronomical Twilight Begin | 04:05 |
| Nautical Twilight Begin | 04:53 |
| Civil Twilight Begin | 05:35 |
| Sunrise | 06:09 |
| Sunset | 20:50 |
| Civil Twilight End | 21:23 |
| Nautical Twilight End | 22:05 |
| Astronomical Twilight End | 22:53 |
| Moon Illumination | 3.07% |