| Geyser | 1999-12-28 |
|---|---|
| Giantess | 0809 ie |
| Grand | 0435 E, 1447 E |
| Great Fountain | 0242 E, 1454 E |
| Values for Old Faithful Area | 1999-12-28 |
|---|---|
| Astronomical Twilight Begin | 06:13 |
| Nautical Twilight Begin | 06:48 |
| Civil Twilight Begin | 07:25 |
| Sunrise | 07:58 |
| Sunset | 16:50 |
| Civil Twilight End | 17:23 |
| Nautical Twilight End | 18:00 |
| Astronomical Twilight End | 18:36 |
| Moon Illumination | 63.42% |