Internal Webpage Label change

In the Internal (Logged In) Interface I want to change the “Calendar” Label to “Schedule”. To me it makes more sense. I did it as shown under version 3.0.0 code but I can’t seem to find where it needs to be changed in 3.1.0. I tried modifying the navigation.php file that has the label listed in the Legacy directory but that didn’t work. Please advise where this value might reside. Thank you. Screenshot included to illustrate.

The Board only allowed 1 screenshot so this is what I want: