It takes a few minutes for marriage
It takes few minutes for marriage. But you have to give 30 days advance notice for that.
When you give the notice, they will display it on their noticeboard, open for public view. If no one objects on your marriage within those 30 days, you can go and marry anyday, within 3 months.
Remember : 30 days notice is required for registered marriage (court marriag, as we call) and not for marriage registration (ie registering after traditional marriage).