Simple Calendar in Linux

Sometimes you will find yourself in Linux, and desire to see very simple calendar. No integrations, no synchronization, just simple table with day numbers. Sadly some DE does not show calendar by clicking on clock (for example if you fancy DockbarX). So what do you do?

You can type cal -3 in terminal and it will show you next and previous month. But way if you want little UI to navigate back and forward in months using buttons? Just type zenity --calendar.