To say ‘have a great weekend’ in French, you would say ‘passe un bon week-end’.
This phrase is quite common in French-speaking countries and is used much like its English counterpart to express good wishes for the weekend. The word ‘passe’ is the imperative form of ‘passer,’ which means ‘to spend,’ and it invites someone to enjoy their time. ‘un bon’ translates to ‘a good,’ and ‘week-end’ is borrowed directly from English and carries the same meaning.
So, when you wish someone ‘passe un bon week-end’, you are essentially telling them to spend a good weekend!