Original sentence: Physically, the meridian of Greenwich in Universal Time is almost always to the east of the meridian in Terrestrial Time, both in the past and in the future
Edited sentence: (The SI second as now used for UTC, when adopted, was already a little shorter than the current value of the second of mean solar time.) Physically, the meridian of Greenwich in Universal Time is almost always to the east of the meridian in Terrestrial Time, both in the past and in the future