How to compare DateTime in C#?

Question

I don't want user to give the back date or time.

How can I compare if the entered date and time is LESS then the current time?

If the current date and Time is 17-Jun-2010 , 12:25 PM , I want user cannot give date before 17 Jun -2010 and time before 12:25 PM.

Like my function return false if the time entered by user is 16-Jun-2010 and time 12:24 PM

Please help!!

Answer 1

MSDN: DateTime.Compare

DateTime date1 = new DateTime(2009, 8, 1, 0, 0, 0);
DateTime date2 = new DateTime(2009, 8, 1, 12, 0, 0);
int result = DateTime.Compare(date1, date2);
string relationship;

if (result < 0)
   relationship = "is earlier than";
else if (result == 0)
   relationship = "is the same time as";         
else
   relationship = "is later than";

Console.WriteLine("{0} {1} {2}", date1, relationship, date2);
// The example displays the following output:
//    8/1/2009 12:00:00 AM is earlier than 8/1/2009 12:00:00 PM

Answer 2

Microsoft has also implemented the operators '<' and '>'. So you use these to compare two dates.

if (date1 < DateTime.Now)
   Console.WriteLine("Less than the current time!");