I have a small medical condition which sometimes causes me to be late. I am just starting my career fresh out of university. I don't want my employer and colleagues to get the false impression that I am coming in late because I over slept. This is not predictable and takes an additional 15-60 minutes. I will be working in the Software industry so the problem is not gigantic but some still have core working hours.
How do I disclose this information without going into to much detail and not have them perceive this as a shabby excuse?