I just always double what I think it will take. I've been doing software now for 20 years and I have NEVER seen something come in on time. If I think it will ta

I just always double what I think it will take. I've been doing software now for 20 years and I have NEVER seen something come in on time. If I think it will take a month, I say it will take two. This has saved me more than I can count since I pad for the unseen circumstances that will occur.