It may be unnoticable, but Friday's earthquake off the coast of Japan did shorten the day by a tiny bit. Read on.
NASA geophysicist Richard Gross was able to calculate that due to the shift in the Earth's mass after Friday's earthquake, the Earth's rotation about it's own axis was sped up by 1.6 microseconds. Shortening each Earth day by 1.6 microseconds.
Friday's 8.9 magnitude earthquake off the coast of Japan was the world's fifth strongest since 1900.
In comparison ,2004's 9.1 to 9.3-magnitude Sumatra earthquake caused a 6.8-microsecond shortening of the day.