Technically, Tuesday is the last night of Hanukkah, and Wednesday day is the last full day of Hanukkah. The holiday is officially over at sundown on Wednesday. But for most non-observant Jewish people who light the menorah (which is the most important way to observe the holiday of Hanukkah), the holiday closes this Tuesday night.
A note for for gift giving purposes: Give your Hanukkah gifts by Tuesday evening. For most people who are not religiously observant, the holiday feels like it ends on the last night of candle lighting. In 2011, that would be Tuesday, December 26.
When Is the Last Night of Hanukkah?Chanukah 2013
Last night of menorah candle lighting: Thursday, December 4
Last night of menorah candle lighting: Wednesday, December 23
Last night of menorah candle lighting: Monday,December 13