$ sudo apt-get update
$ sudo apt-get install libecal-1.2-16 

libecal-1.2-16 is installed in your system.

Make ensure the libecal-1.2-16 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libecal-1.2-16 *

You will get with libecal-1.2-16 package name, version, architecture and description in a table

libecal-1.2-16 package basic information: