Text is incorrect on user edit form

Current text:

Leave blank for indefinite time, enter date and time in format: yyyy-mm-dd hh:mm:ss or use relative time i.e. 1 day, 2 months, 1 year, 3 years.

The text doesn't mention that if a default expiration is set for the selected role, an expiration will be automatically set in the next cron run.

I'd make a suggested patch, but I am working against a deadline for a client's project. Perhaps later.