On April 21, 2015, Google released a significant new mobile-friendly ranking algorithm that is designed to give a boost to mobile-friendly pages in Google mobile search results.

The change, which will take about a week to complete, is so significant that the date it actually happens is being referred to by a variety of names, such as mobocalypse.

All website owners, that desire business from mobile phone users should test to see if Google considers their web site to be mobile-friendly by using Googles Mobile-Friendly Test tool.

The algorithm started rolling out on April 21st and will take a few days to a week to complete globally. You are either mobile-friendly or not, there are no degrees of mobile-friendliness in this algorithm.  Read more about how this will affect your business rankings with Google here.  The best way to see if your web pages are mobile-friendly is to check the Mobile-Friendly testing tool from Google.