Grampound blind darts team at The Dolphin

http://www.itv.com/news/westcountry/2014-10-23/meet-the-uks-first-blind-darts-team/

http://www.westbriton.co.uk/Blind-darts-team-takes-aim-ahead-inaugural-match/story-23182497-detail/story.html

http://www.dailymail.co.uk/news/article-2800091/britain-s-blind-darts-team-called-optimists-use-string-help-hit-bullseye.html

http://i100.independent.co.uk/article/meet-britains-first-blind-darts-team-theyre-called-the-optimists--lJBV4HjuUl

http://i100.independent.co.uk/article/meet-britains-first-blind-darts-team-theyre-called-the-optimists--lJBV4HjuUl

http://metro.co.uk/2014/10/20/watch-blind-darts-players-take-aim-using-a-piece-of-string-4913296/

When does next weekend become this weekend?

On a Friday you would say 'this weekend' referring to the next 2 days and 'next weekend' would be over a week away. On the Saturday and Sunday 'this weekend' would mean those two days and 'next weekend' would be a week away.

On a Monday 'this weekend' could still mean 'this weekend [just gone]' and 'next weekend' could be now less than a week away. The weekend after that is 'the weekend after next'.

At some point in the week it changes and the weekends all shuffle along. 'This weekend [just gone]' becomes 'last weekend'. 'next weekend' becomes 'this weekend' and 'the weekend after next' becomes 'next weekend'.

What I want to know is when does it change? Is that somewhere on a Wednesday? If so, when? At Midday (GMT) on a Wednesday what would 'this weekend' refer to?

Just asking.