Quote Originally Posted by Guido van den Berg View Post
In the weekends, some time slots are reserved for association matches. You cannot plan a friendly game in those time slots.
You are right about slots being reserved for association matches part but his case seems to include another bug or problem. In some countries, it's not possible to arrange instant friendly during fixed time period of every hour, like in my case 45th to 59th min of every hour. It varries country wise.