[TYPO3-seminars] onetimeaccount date picker

[Dirk Fischer]

Hi,

in the registration form is a date picker for birthday.
It ist unformatted ... not easy to use.

I included the static templates:
MKFORMS - Basic
MKFORMS - jquery-js (if I use protype nothing happens with date picker 
on click)
onetimeaccount
seminars

All extensions in latest version for TYPO3 7.6
oelib 2.0.1
onetimeaccount 3.0.0
rn_base 1.8.2
mkforms 3.0.21
seminars 2.0.1

Is there a CSS I can include for the date picker or ist something wrong 
with jquery?

Thanks for any hint.

Best regards
Dirk