GameStop Italy may have revealed the launch date of Fallout 4 as October 23rd, that's also the date in 2077 when China and the United States engage in the devastating nuclear war which destroys most of civilisation, so it would certainly be an appropriate release day.
October 23rd is a Friday, which has become increasingly popular for releases in North America (most recently for Nintendo shooter Splatoon) and has been the standard launch day in the UK and Ireland for years.
Numerous other retailers, including GameStop in the US and Amazon, currently list the holding date of December 31st, 2015, while Bethesda's own store briefly declared that the game would be released in 2015 yesterday before the listing was changed to 'TBA'.
Bethesda is set to reveal more of Fallout 4 during their first ever E3 press conference on Sunday, June 14th at 19:00 PST/22:00 EST/03:00 BST and we may learn the release date then.
Fallout 4 is coming to PC, PS4, and Xbox One and you can watch the announcement trailer here if you somehow missed it yesterday.