I just tested this again with the most recent 1.8+ code base, still behave the same way and I couldn't find any ticket about this in moodle bug tracker. Basically if the user select an invalid date open and/or close date, such as Feb 31st, and Apr 31st, moodle 1.8 (and 1.8+) will change those inputs to valid dates automatically but might not be the date that the users want (see screenshots)
reproduce procedure:
- Setup a quiz with an invalid open and close date (e.g. Feb 31st, Apr 31st).
- Leave other setting to be default.
- “Save changes”
It would be good to give a warning message and refocus on that field for the users to change the dates into a valid one, instead of fixing it automatically (plus two days?) and quietly.