Question

I have two Classes which are made up of two DateTime values. A start Date and an End Date.

Basically, I need a way of checking if one of the classes Start Date – End Date range intersects with the other Classes’.

Is there an easy way to do this?

Cheers.

Answer 1

Here are the possible ways in which the time can overlap (assuming one object starts earlier and one starts later).

time  ----------------------------------------------------------> 

(complete overlap) 
earlier :     start |------------------------------------| end   
later   :          start |--------------------------| end

(partial overlap) 
earlier :       start |--------------------------------| end
later   :           start |--------------------------------| end   

(start date matches)
earlier :       start |----------------------------------| end
later   :       start |----------------------------------| end

(no overlap)
earlier :       start |------------| end
later   :                                start |--------| end       

If that’s the case, you can do the following to check (though there’s

var earlier = obj1.start < obj2.start ? obj1 : obj2;
var later   = obj2.start < obj2.start ? obj1 : obj2;

if (later.start < earlier.end)
{
    Console.WriteLine("Object 1 overlaps with Object 2");
}