The Lunar Festival lasts from February 5th to February 23th, approximately. Very simple quests associated with the Lunar Festival provide some unique travel opportunities for the duration of the festival. An invitation to the festival (found in all but the Draenei and Blood Elf capital cities) allows the bearer to teleport to Moonglade. The hill on which you arrive contains one circle of moonlight for each non-Burning Crusade capital city. Using the invitation within one these circles teleports you back to one of these cities (they are marked off by the races dancing around the circle). So if, for example, you teleported into Moonglade from Stormwind, once the invitation's 10 minute cooldown elapsed, you can then teleport to, say, Darnassus.