how can I configure on a (birthday)date field a +18y old verification check?

PHP 8.4.22
Joomla 5.4.6
CB 2.11.0
database MySql 8.0.30

Hi Support,
I'm running CB + CB Paid Subscriptions to register members of a sportclub and have then annual paid memberschip fee.
During registration, new members have to provide their date of birth: CB fields type 'Date'. In the field definition parameters => validation I provide a min. -18 and max -100.
I am not allowed to accept members of -18years due to legal requirements not met for working with minors.
I expected the validation rules would verify that at registration the new member is +18y based on the birthday date provided.
It now turns on that this only checks wether the year of birth is more then 18y ago, but does accept registration by people who are in between 17 and 18 at the date of registration.
Is there any other way I can check that at today they effectively turned 18?In other words that the date provided in the birthday field is effectively more then 18 year ago compared to today's date?

Thanks, best regards

Edit your Date field then within Parameters > Display set "Profile View Display" to "Age", "Birthday", or "Birthday, with Age". Now under Parameters > Validation set the "Minimum Age" and "Maximum Age" as needed.

Thank you! Question solved. 
You guys are amazing me every time again.