How to subtract a datetime from another datetime?

How to subtract a datetime from another datetime: 

DateTime date1;
DateTime date2;
Long diff_Ticks = (date2 - date1).Ticks;
DateTime d1 = DateTime.Now;
DateTime d2 = DateTime.UtcNow;

var result = d1 - d2;

double date_Result = result.Ticks;
DateTime startTime = DateTime.Now; 
DateTime endTime = DateTime.Now.AddSeconds(70);  
TimeSpan span = endTime.Subtract ( startTime );
Console.WriteLine( "Time Difference (days): " + span.Days ); 
Console.WriteLine( "Time Difference (hours): " + span.Hours ); 
Console.WriteLine( "Time Difference (minutes): " + span.Minutes ); 
Console.WriteLine( "Time Difference (seconds): " + span.Seconds ); 


var Date1 = new DateTime(2018, 12, 14);
var Date2 = new DateTime(2019, 1, 02);
TimeSpan result1 = Date2.Subtract(Date1);
Console.WriteLine(result1);

Note: Date2 should be greater than Date1 or else the method will return a negative value

2020-05-31