Tomorrow (28 June) is the anniversary of the assassination in Sarajevo which would prove to be the spark that would ignite into a worldwide war. Though various commemorative events have already occurred, and the BBC has also already begun it’s related programming, this is the date which quick the commemorations into high gear.
28 June sees various events in Sarajevo itself, including a concert by the Vienna Philharmonic which will be broadcast around Europe. Also the BBC will be running a “live” blog, reporting on the day as it happened, but with analysis from their current team of correspondents. All at http://www.bbc.co.uk/news/live/world-27978407. A special Foreign Office twitter account (@WW1FO) will also begin a series of tweets based on the information originally received from British Embassies around Europe in 1914.
There’s also a full day conference at The National Archives, looking at the diplomatic situation in the lead up to the war, and thereafter. Various other organisations have their own events going on too.