Hi all I am currently working on a project where when a certain event happens details about the event including the time that the event occurred is added into a list array.
Once the method has finished I then pass on the list to another method that checks its values. Before I go through the loop I check the current time of my PC and I need to check whether the difference between the time saved in the list array and the current time is greater than 5 seconds.
How would I go about doing this.
Assuming dateTime1 and dateTime2 are DateTime values:
var diffInSeconds = (dateTime1 - dateTime2).TotalSeconds; In your case, you 'd use DateTime.Now as one of the values and the time in the list as the other. Be careful of the order, as the result can be negative if dateTime1 is earlier than dateTime2.
DateTime has a Subtract method and an overloaded - operator for just such an occasion:
DateTime now = DateTime.UtcNow; TimeSpan difference = now.Subtract(otherTime); // could also write `now - otherTime` if (difference.TotalSeconds > 5) { ... } This version always returns the number of seconds difference as a positive number (same result as @freedeveloper's solution):
var seconds = System.Math.Abs((date1 - date2).TotalSeconds); I use this to avoid negative interval.
var seconds = (date1< date2)? (date2- date1).TotalSeconds: (date1 - date2).TotalSeconds; 
Math.Abs instead, this code is less readable and performant than just using the answer above.The built-in DateTime.Subtract method can be used as follows
double diffInSeconds = dateTime1.Subtract(dateTime2).TotalSecond; if (diffInSeconds > 5) { /* do stuff */ } ; for .NET Framework
int ticks = Environment.TickCount; /* Do something */ ticks = Environment.TickCount - ticks; // difference in milliseconds string elapsed = String.Format("Elapsed time: {0} s", (ticks/1000).ToString()); for repeated measurement
int start_ticks, ticks; string elapsed; start_ticks = Environment.TickCount; /* Do something */ ticks = Environment.TickCount - start_ticks; // difference in milliseconds start_ticks += ticks; elapsed = String.Format("Elapsed time: {0} s", (ticks/1000).ToString()); /* Do something */ ticks = Environment.TickCount - start_ticks; // difference in milliseconds start_ticks += ticks; elapsed = String.Format("Elapsed time: {0} s", (ticks/1000).ToString()); with .NET Core it's better to use 64-bit TickCount64
long ticks = Environment.TickCount64; ticks = Environment.TickCount64 - ticks; 