Problem
Users cancel booking process at the last step due to misleading UI: On a listing site the user cannot see available dates once she selected a time period on the calendar. She is forced to click on "clear" first which is not very intuitive. Before clicking on CLEAR all dates including the available ones are shown with the CSS Property text-decoration: line-through. The problem is users ignore the clear button. I conducted a couple of usability tests and 4/5 users got confused at this point, thinking that there are no further dates available and completely ignoring the clear-button. This means I miss out on revenue and lose customers at the very last step.
Solution
Only non-available dates should have a text-decoration. Keep showing available dates as black or at least greyed out to help me as a user understand which other dates are available. Ideally, as a user I can select new dates without having to click on the clear button at all. This allows me to browse through the calendar to check for alternative dates as an intuitive next step.