Date Arithmetic

I am working this weekend on a major data migration. I have several millions records to manipulate, store, and index. I needed a way to calculate how long the process was going to take. Once I had it in hours, I still needed an easy way to figure out the end time. Instead of trying to do the math in my head, I figured there had to be a site that would calculate that for me. Sure enough there is and it's nicely done. Here's a link: http://www.timeanddate.com/date/timeadd.html.