V3118. A component of TimeSpan is used, which does not represent full time interval. Possibly 'Total*' value was intended instead.

The analyzer detected an expression accessing the property 'Milliseconds', 'Seconds', 'Minutes', or 'Hours' of an object of type 'TimeSpan', which represents a time interval between several dates or other time intervals.

This expression is incorrect if you expect it to return the total number of time units in the interval represented by the object, as the property you are accessing will return only part of that interval.

Consider the following example:

var t1 = DateTime.Now;
await SomeOperation(); // 2 minutes 10 seconds
var t2 = DateTime.Now;
Console.WriteLine("Execute time: {0}sec", (t2 - t1).Seconds); 
// Result - "Execute time: 10sec"

We write the date and time before executing an operation to the 't1' variable, and the date and time after executing the operation to the 't2' variable. Suppose that it takes exactly 2 minutes 10 seconds for the 'SomeOperation' method to execute. Then we want to output the difference between the two variables in seconds, i.e. the time interval of operation execution. In our example, it is 130 seconds, but the 'Seconds' property will return only 10 seconds. The fixed code should look like this:

var t1 = DateTime.Now;
await SomeOperation(); // 2 minutes 10 seconds
var t2 = DateTime.Now;
Console.WriteLine("Execute time: {0}sec", (t2 - t1).TotalSeconds);
// Result - "Execute time: 130sec"

We need to use the 'TotalSeconds' property to get the total number of seconds in the time interval.