It's pretty common around here for firms that don't "face" the customers (a software shop is a perfect example) to install magnet locks with RFID card readers at the office entrance, and give the key cards to the workers (and the office building owners, obviously). Throw in some primitive software to count timestamps of enters/exits, and here's your punch clock for the digital era.

Are they having you swipe when you exit as well?

Yes, there is a reader on the inside too.