New Zwifter here. When filling out my profile for my data of birth, the radio dial for date will not advance beyond the 28th. Sadly I was born on the 30th. There are months other than February you know.
They sent me a happy birthday email a week early, so I’m guessing that accurate birthdays aren’t a big priority. 
That’s still an „issue“, Dave. 
Got my email today, 8 days early. 