Though there are examples of happy long marriages that were registered after 2 days of dating, you should be ready and aware that you are dating a real woman who is not perfect. It takes time to know the dark side of your future partner. 3 – 12 months will be good enough to find out if you both are ready to stand each other's bad mood and compromise when you have different views on the subject. If you are not sure this lady is yours even after 12 months of dating, this lady is not yours actually.