Need help with rangevalidator

Hey i am using a rangevalidator in my program but i have a problem with the maximumvalue option of a rangevalidator. The minimum must be the day of today thats easy to
program but te maximumvalue has to be 1 year later the today. i dont know how i can program this .

Thanks in advance

 

I know its too late..but im sure this may help someone else who would be searching for this solution...

PHP:

        RangeValidator1.MinimumValue = DateTime.Now.ToShortDateString();
        RangeValidator1.MaximumValue = DateTime.Now.AddYears(1).ToShortDateString();