If your having a church ceremony this will take around 45mins/1hr and if having a civil ceremony this will take around 20/30mins. It all depends on what readings and music you decide on during the service.
A civil ceremony followed by reception may look like this but a church service has no interviews on the day.
12.30 registrars arrive and interview groom
12.30 bride arrives
12.45 registrars interview bride
12.45 guests arrive
1.30 mr & mrs exit and enjoy celebration drinks at reception venue with guests and photos with family and friends
3/3.30 wedding meal to commence
6.00 meal finish/coffees/cut cake