From SpaceflightNow.com: NASA clears shuttle Atlantis for a May 14 lift off on the 25-year-old orbiter’s final scheduled mission. The launching period will last through May 18. After four launch attempts in five day, the 12-day flight will slip to late June to accommodate other launches and activities at the International Space Station.
http://www.spaceflightnow.com/shuttle/sts132/100505frr/