How to select a value from Calendar using Selenium Webdriver
First need find css for calendar object
css=label[id='flight-departing-label']>span.icon.icon-calendar.
driver.findElement(By.cssSelector("input#flight-type-roundtrip")).click();

1. Verify month
driver.findElement(By.cssSelector("div.cal>section.cal-month:first-of-type>header>h2")).getText();
It will return the month Nov 2014
2.Select the day
driver.findElement(By.cssSelector("div.cal>section.cal-month:first-of-type>ul>li>a[data-day='6']")).click();
3. Clicking next month like Jan 2015
driver.findElement(By.cssSelector("button[class='btn-paging btn-secondary next']")).click();