I just replied to your other post.
Copying and pasting
It depends on you and the other person. You may be convinced in 2 months, or not even if in a year.
Typically 3-6 months, but can go up.
Try to get these things accomplished -
You are friendly and comfortable around each other.
Have discussed all the main points, deal breakers etc.
Have spent good amount of time together alone, doing something together (stay in different rooms at night if you have taboo). Spend at least 12-18 hrs at a stretch for a few days, or take a small vacation together. Take up some project together like organizing a family dinner etc.
Know each other's bathroom habits
Know then in informal setting, i.e, in clothes they wear at home, in a relaxed setting