Operating system: MacOS 10.11.6
Graphics card: GT 750M
Broken: 2.80, e78770039397
Short description of error
The Timeline numbers on a Retina disaply are too cramped together. I guess the logic by which it switches from 5 steps to 10 steps etc to have more space between the numbers doesn't take High DPI / Retina into account
Exact steps for others to reproduce the error
Here's the default startup on a MacBookPro with Retina Display the timeline with Blender running on a regular display.