There is 1 calendar, that shows only birthday dates from contacts on iphone/mac OS. But if 1 contact has several dates (e.g. jubilee, birthday of kids or other important dates) that i want to be shown in calendar on iphone or mac OS.
How can it be done? And can it?
Nope. You can add custom dates in Contacts
and create repeating events in Calendar,
but there's no automatic linkage between the two. The best you'll get is something like BirthdayScanner which scans all dates in Contacts then allows you to add them to your Calendar, but there's no first-party automagic solution.