Well really, you add stuff by stealing it from other countries and bringing it back to yours. Of course, the UK did quite a lot of that during times of Empire...
The 14 states you missed are: Franklin, Jefferson, Superior, Delmarva, Absaroka, Scott, Transylvania, Deseret, Cascadia, Lincoln, Atlantica, New Amsterdam, Sequoia, and Dixie.
It's not just time zones and leap seconds. SI seconds on Earth are slower because of relativity, so there are time standards for space stuff (TCB, TGC) that use faster SI seconds than UTC/Unix time. T2 - T1 = [God doesn't know and the Devil isn't telling.]