May is National Bike Month
The month of May is the official National Bike Month as designated by the League of American Bicyclists.

As part of National Bike Month, communities around the country sponsor activities and events to celebrate bicycling and get people riding. A focus of the month is Bike-to-Work Week from May 12-16, and Bike-to-Work Day on Friday, May 16.
In addition, the League of American Bicyclists offers a list of 50 ways to celebrate Bike Month.