For the Earth-Moon system, d"r"/d"t" gives 1.212×10−9 meter per second (or nm/s), or 3.8247 cm per year (or also m/cy)[24]. This is a 1% increase in the Earth-Moon distance in 100 million years. The deceleration of the Moon d"n"/d"t" is -1.2588×10−23 radian sec−2 or -25.858 "/cy2, and for a period of 29.5 days (a synodic month) is equivalent to an increase of 38 ms/cy, or 7 minutes in 1 million years, or 1 day (i.e. lengthening of the lunar period in 1 day) in 210 million years.