C# Formatting Age - Regarding Days, Weeks , Months - Years

Question

I am working on some medical software and I am required to output all ages in a very specific manner, based on the following rules:

 If under 6 Weeks old :           


        

Answer 1

I was working on something similar yesterday, but something like this should suit your needs: (assuming 7 day weeks, 31 day months, 365 day years etc.)

Revised Method : (Fixed as per Bob's suggestions)

public static string ConvertAge(DateTime dob)
    {
        DateTime today = DateTime.Today;
        string fmt = "{0:0##}{1}";

        //Greater than 2 Years old - Ouput Years
        if (dob <= today.AddYears(-2)) 
            return string.Format(fmt, (dob.DayOfYear <= today.DayOfYear) ? 
            (today.Year - dob.Year) : (today.Year - dob.Year)-1, "Y");
        //Less than 2 Years - Output Months
        if (dob < today.AddMonths(-2)) 
            return string.Format(fmt, (dob.DayOfYear <= today.DayOfYear) ? 
            (today.Year - dob.Year) * 12 + (today.Month - dob.Month) : 
            ((today.Year - dob.Year) * 12 + (today.Month - dob.Month))-1 , "M");
        //Less than 2 Months - Output Weeks
        if (dob < today.AddDays(-2 * 7)) 
            return string.Format(fmt, (today - dob).Days / 7, "W");
        //Less than 2 Weeks - Output Days
        return string.Format(fmt, (today - dob).Days, "D");
    }

Previous Method :

public string ConvertAge(DateTime dateOfBirth)
        {
            int daysOld = (DateTime.Now - dateOfBirth).Days;

            //Age < 6 Weeks
            if (daysOld < (6 * 7)) 
                return String.Format("{0:0##}{1}", daysOld, 'D'); 
            //Age < 6 Months
            else if (daysOld < (6 * 31)) 
                return String.Format("{0:0##}{1}", daysOld/7, 'W');
            //Age < 2 Years
            else if (daysOld < (2 * 365)) 
                return String.Format("{0:0##}{1}", daysOld / 31, 'M');
            //Age >= 2 Years
            else 
                return String.Format("{0:0##}{1}", daysOld / 365, 'Y');
        }

Hope this helps!