How long does it take to port a number from "land-line" to T-mobile phone?

I want to port the phone-number of my land-line (currently carried by Comcast Xfinity) to my T-mobile phone (replacing the number the T-mobile phone presently uses). I confirmed on T-Mobile's website that the number can be ported.

1. How long does this usually take to complete the port?
2. Would I have to get a new sim card?

Thanks in advance