I use Khard for contacts and khal for calendar.

Neither handle syncing, so I use vdirsyncer for that (you can use anything you like or just go local only).

https://github.com/scheibler/khard

https://github.com/pimutils/khal

https://github.com/pimutils/vdirsyncer

I currently use Thunderbird for mail, and MineTime for calendar. I found the Thunderbird calendar integrations (5 calendars) way too flaky.

Would be good to have a calendar client in terminal.

MineTime looks cool, but I got a wrong feeling about the looks and yeah, scrolling down and I saw it: "MineTime is a calendar built on Electron". Nah, I prefer to have just one browser open (and not Chrome/Chromium).

Have a look at vdirsyncer, khard, and khal. This in combination with mbsyc is my CLI PIM sync :)