C#: how do I subtract two dates?

Question

Here\'s my code:

DateTime date1 = new DateTime(byear, bmonth, bday, 0, 0, 0);
DateTime datenow =  DateTime.Now;
DateTime date2 = datenow - date1

Answer 1

You are expecting the difference of two dates to be a date which is not. That being said, if you need to subtract a certain number of days or months, it can easily be done using the built in methods of the DateTime object such as .AddDays(-1), note that I used a negative number to substract, you can apply the opposite. Here is a quick example.

        DateTime now = DateTime.Now;

        // Get the date 7 days ago
        DateTime sevenDaysAgo = now.AddDays(-7);

        // Bulk: Get the date 7 days and two hours ago
        DateTime sevenDaysAndtwoHoursAgo = now.Add(-(new TimeSpan(7, 2, 0, 0)));