As as soon as you enter Tomorrowland from Main Street The Timekeeper (which was permenantly closed earlier this year) will be on your right. It is across from Stitch's Great Escape and coming from the direction, it is just before Buzz Lightyear.
Diamond Horseshoe is in Liberty Square, It is just past the Liberty Tree Tavern restauarant right before Libertyb Square switches over to Frontierland (would be on your left if heading toward Frontierland).