I have three integers: Hours, Minutes, and Seconds.
I want to create a DateTime object with System.Date and Time provided by the above three variables.<
You can use DateTime.Today to get the current date at midnight, and add the hours you need by using a TimeSpan, which is a good way to represent hours of the day:
TimeSpan time = new TimeSpan(12, 20, 20); // hours, minutes, seconds
DateTime todayWithTime = DateTime.Today + time;
See also: