Suggest registration time at event creation

Ghost User
2019-10-24T22:19:23+02:00

### One-sentence description I would like to show event organisers to not open registration at 13:37 but at 12:30. ### Motivation Event organisers often open registrations at 13:37, but this is a time when many people have lectures, so a suggestion text at this field would help with that. ### Desired functionality Help text at registration opening time. ### Suggested implementation Have a help text at event creation registration time that reads "Prefer opening times at which people don't have lectures, so 12:30 instead of 13:37"