>>>>>>Hi,
>>>>>>
>>>>>>I want to calculate the age in years so I have this code:
>>>>>>
>>>>>>

        public static int CalculateAge(DateTime? StartDate, DateTime CurrentDate)
>>>>>>        {
>>>>>>
>>>>>>            int YearsPassed = CurrentDate.Year - StartDate.Year;
>>>>>>            // Are we before the birth date this year? If so subtract one year from the mix
>>>>>>            if (CurrentDate.Month < StartDate.Month || (CurrentDate.Month == StartDate.Month && CurrentDate.Day < StartDate.Day))
>>>>>>            {
>>>>>>                YearsPassed--;
>>>>>>            }
>>>>>>            return YearsPassed;
>>>>>>        }

>>>>>>
>>>>>>I call this code like this:
>>>>>>
>>>>>>

int policyYear = CalculateAge(this.Entity.IssueDate, DateTime.Now);

>>>>>>
>>>>>>this.Entity.IssueDate could have a null value. Of course I get errors like this:
>>>>>>
>>>>>>

'System.Nullable<System.DateTime>' does not contain a definition for 'Year' and no extension method 'Year' accepting a first argument of type 'System.Nullable<System.DateTime>' could be found

>>>>>>
>>>>>>I've tried putting an if {this.Entity.IssueDate != null} around my call to the function and making th eparameter not nullable, but that hasn't worked. How do I adjust this code to work?
>>>>>
>>>>>That would depend on what you want to happen when Entity.IssueDate is null........
>>>>
>>>>If it's null, then I don't want the calculation to be done.
>>>
>>>Then I guess there's no need to have the method accept a nullable value:

public static int CalcAge(DateTime StartDate, DateTime EndDate)
>>>        {
>>>//....
>>>        }

so

if (IssueDate != null)
>>>            {
>>>                int age = CalcAge((DateTime)IssueDate, DateTime.Now);
>>>            }

>>
>>Thanks, that's what I ended up doing. :)
>>
>>Is this way better than what Bonnie suggested?
>
>I don't think its better. AFAIK the difference between IssueDate.HasValue() and IssueDate==null is just a readability issue.
>But
> DateTime t = IssueDate.Value;
>removes the need to cast as in:
>DateTime t = (DateTime) IssueDate;

Tahnks, I think I've got it.