.

May I inquire as to why you want to use a a complex variable to pass two dates? Seems it would be much simplier to pass two variables each containing one date to your procedure. Anyway using what you have posted try this:

ALTER PROCEDURE PrintMessage

@variable VARCHAR(30)

@var2 VARCHAR(30)= ' '

AS

PRINT @variable, +' ' + @var2

--testing

DECLARE @variable VARCHAR(30)

SET @Variable = 'Print message'

EXECUTE PrintMessage @Variable, 'some more text'

Result

Print message some more text

or

DECLARE @variable VARCHAR(30)

SET @Variable = 'I will Print message'

EXECUTE PrintMessage @Variable

Result when only one variable is passed to the procedure:

I will Print message

Again I would urge you to follow the KISS principle (Keep It Simple S-----)