Busymac.com [created by the original developers of Now-Up-To-Date and Contact] just released BusyCal 2.6.4 and BusyContacts 1.0. These are the modernized versions of Now-Up-To-Date and Contact for which we've been waiting years. Yay!
The key now is how to convert from NUTD and C to BusyCal and BusyContacts.
BusyCal and BusyContacts are powerful in that they also synchronize with Office365 and iCloud. So you now have the capability of updating your calendars on your iPhones and iPads and all your Macs.