I don't subscribe but a quick look at the site shows 'Tuesday 17 April 2018' at the top of the page. Perhaps the site is configured to use GMT, meaning that (at this time of year) pages don't get updated until 1am?
I've just been pressing F5 (to refresh the page) every few seconds on that site as 1am was approaching. As I suspected, Wednesday started at exactly 1am (with today's crosswords appearing at the same time)