You are required to arrive at least 3 business days before your wedding (ie do not include weekends!) and to remain in Turkey one business day following your wedding, to register your marriage with the UK Consul office.  We manage this process fully for you..
Therefore, if you are marrying on a Wednesday, you need to arrive at least the Friday beforehand to allow enough to meet with the wedding team and to visit the UK Embassy in Antalya, which takes one full (business) day.