The deadline is 3:00pm PDT, April 5, 2019.
The reason I am posting this is that there is a fake FOCS website that ranks first or second on searches for “FOCS 2019”. The website is under the domain “aconf dot org” (I don’t want to increase ranking and traffic to it even further by linking to it). This website contains fake pages for many other conferences, and in fact sometimes is ranked highly enough in searchers that conference organizers mistakenly link to it in their own web page. Apparently it is owned by a company called Chaytey who also has a similar webpage for journals under the address xjournal dot net. (Thanks to Sara Cohen ,colleague of FOCS general chair Yuval Rabani for finding this out.)