Its a Date Data Type

Its not working , I got this message :

Msg 241, Level 16, State 1, Line 1

Conversion failed when converting date and/or time from character string.

I don't have a problem to get a random month or a day I just using this :

UPDATE table_a

...

If I want to select it's working but as I mentioned I'm trying to insert and because my column is a 'date type' when I'm using CONVERT(VARCHAR(7), GETDATE(), 111)-- AS...