How long?

I knew my husband just under a year when we became engaged.  We had a long engagement though....so we were together for 3 years before the wedding.  I wouldn't suggest that.  Too much temptation.  Getting to know the person is important, I suggest a short engagement though.  A year sounds good.  4 years is a bit much, 2 months I feel is not enough time to see a persons true colors. 

Remember, this is the person you are going to spend the rest of your life with.  This is going to be the father of your children and their role model.  You want to make sure you are making the right choice.  You want a good man who will be a great father and good provider.  If he has a temper, you should be able to see that within a year.  I know few people how can play a role for that long without breaking character.

Bismillah,

I don't think time is the best measure for this, although it is a start and a good guideline.  We are instructed in the Hadith that we don't know a person until we have seen them in many different aspects of life such as business, personal, at home with his family, at work with his peers, with children, under pressure, with money problems, without money problems and on and on.   Did you read Ummziba's list of questions for a proposed spouse?  It's here under Sisters.  Asking thorough questions on important personal issues encourages a marriage with mutuality and companionship.