What is the apt time to marry a girl about a man ?

I think you can marry at the age of forty

It differs with the country you live in.I am from India and here the right age for a girl to get married is 21 and some girls are married at the age of 18 and not below that.In western countries,living together is happening at a very early years of life.So,this cannot be generalized.Cheers!

You can't really put a number on it. It is when you feel ready and know you have enough of a connection with your partner to pursue the next step. I would say a week into a relationshp would be too early but hey even then the magic marriage fairy might make the couple that gets married after a week stay together forever. In conclusion it's really up to the person.