Mavericks is just around the corner, but there are still features I have not discovered in the current version of OS X. Like changing multiple events in Calendar at once by simply moving them around.
Use the usual SHIFT key to select multiple events. With all of your events selected, hold down both the CONTROL and ALT keys and then press the up or down keys or left and right keys to move the event times.
Apple's attention to detail keeps amazing me. Hat tip to Il The Han.