Scientists using the Hubble Space Telescope have determined that a day on Uranus is 28 seconds longer than previously thought, taking 17 hours, 14 minutes, and 52 seconds to complete a rotation. By tracking auroras, a French-led team was able to establish a more accurate rotation period for the ice giant. This new method could be applied to other planets with auroras and magnetospheres to determine their rotation. The findings were published in the journal Nature Astronomy just before the 35th anniversary of the Hubble's launch.
Source: https://abcnews.go.com/Technology/wireStory/day-uranus-28-seconds-longer-120561686