| Geyser | 1981-09-20 |
|---|---|
| Echinus | 1302:46 |
| Veteran | 1329 |
| Values for Old Faithful Area | 1981-09-20 |
|---|---|
| Astronomical Twilight Begin | 05:30 |
| Nautical Twilight Begin | 06:05 |
| Civil Twilight Begin | 06:39 |
| Sunrise | 07:08 |
| Sunset | 19:24 |
| Civil Twilight End | 19:53 |
| Nautical Twilight End | 20:28 |
| Astronomical Twilight End | 21:03 |
| Moon Illumination | 56.74% |