Was looking up mine while you posted yours. Yours looks like it gives more advance notice. I'm religiously opposed to deleting posts, however, so I'll just upvote yours.
I like the name "International Earth Rotation Service" - I always picture some dusty cavern with a giant brass gear wheel and a little old guy coming in with a key every day to wind it up.
http://www.usno.navy.mil/USNO/time/master-clock/leap-seconds
they get if from IERS
http://www.iers.org/
They issue leap second guidance to about 1 year in the future. They adjust typically twice a year as needed (Jan 1 and July 1).