26 June

On 26 June 2010, Amy Pond and Rory Williams got married. (TV: The Big Bang)

In an aborted timeline before Big Bang Two, on the same date, an unknown force triggered the explosion of the TARDIS and caused cracks in the universe. If this timeline had been allowed to pass, the final result would have been a total event collapse. The Doctor instead piloted the Pandorica into the heart of the explosion and cancelled it out, preserving his TARDIS and allowing a new timeline to assert itself. (TV: The Pandorica Opens, The Big Bang)

Amongst the other notable things that occurred on this day were:
 * 1284 - The Pied Piper, in reality an energy entity from the Jeggorabax Cluster, kidnapped a hundred thirty children from the town of Hamelin, Germany to instil fear in the populace. (TV: The Day of the Clown)
 * 1890 - The Eleventh Doctor took Amy Pond and Rory Williams to the recently opened Savoy Hotel for their tenth wedding anniversary. He assured them there would be no complications, only to discover there was a Zygon ship under the Savoy, and half of the staff were imposters. Though the Doctor managed to deal with this. (TV: The Power of Three)
 * 1965 - Ian Chesterton and Barbara Wright returned to Earth using the Dalek time machine. (PROSE: The Time Travellers)
 * Year of the Slow Invasion - The Ponds celebrated their tenth wedding anniversary. The Eleventh Doctor showed up and took them for a bit of sight-seeing on the TARDIS. They "got sidetracked," and ended up returning 7 weeks later, in their perspective. Technically, though, they'd only been gone for 20 minutes. (TV: The Power of Three)

Behind the scenes
This was one of only three instances where a new series Doctor Who television story, namely TV: The Big Bang, took place on the same day as its broadcast: 26 June 2010. The other two occurrences were 22 April 2011 and 25 December 2009.