| Geyser | 1999-12-25 |
|---|---|
| Grand | 0556 E, 1808 E |
| Great Fountain | 0622 E, 1602 E |
| Values for Old Faithful Area | 1999-12-25 |
|---|---|
| Astronomical Twilight Begin | 06:12 |
| Nautical Twilight Begin | 06:47 |
| Civil Twilight Begin | 07:24 |
| Sunrise | 07:58 |
| Sunset | 16:48 |
| Civil Twilight End | 17:21 |
| Nautical Twilight End | 17:58 |
| Astronomical Twilight End | 18:34 |
| Moon Illumination | 90.59% |