Scientists predict that Earth's rotation will accelerate in the coming months, resulting in slightly shorter days. On specific dates in July and August, days will be between 1.3 and 1.51 milliseconds shorter than the usual 24 hours. This change is attributed to the moon's position in relation to Earth's equator, altering its gravitational impact on the planet's axis. Historically, Earth has rotated faster, with days lasting only 19 hours around one to two billion years ago due to a closer moon. Recent fluctuations in Earth's rotation speed have been observed, with 2020 marking the fastest rotation since the 1970s. Timekeepers may need to consider subtracting a "leap second" to maintain atomic clock accuracy if Earth's spin continues to increase. (Newser)