Google has been rolling out the anticipated pre-announced algorithm algorithm changes starting in the US and moving across the globe. Google is boosting the rankings of mobile-friendly web pages on mobile search results. They are trying to give their mobile search users a better mobile experience with the results they are delivering.
This has no affect on desktop searches, but if you are 99% of all businesses, more than half your online searches are done via a mobile search.
Google said there were 4% more mobile-friendly websites on 4/21 than on 4/20. Good job, Last-Minuters (UmmHmm).