operator overloading PLEASE help

[UGAman22]

Hi I am creating a class called time and we've had to do operator overloading for <, > , <=, >=, ==, !=, ++, --, >>, <<, * , +, and -.

Well I have done and error checked them all. The only one I cannot seem to get right is the minus and its because of the error checking. I am having issues with times like this

t1 = 0:0:2:3
t2 = 0:0:1:4

t1 - t2 should equal 0:0:0:59 but it returns 0:0:1:-1.
(days:hours:minutes:seconds)
I need it to check for all cases and I just do not know how.
PLEASE HELP!

  time operator- (const time& x, const time& y)
{

    time subtract;
    subtract.days = x.days - y.days;
    subtract.hrs = x.hrs - y.hrs;
    subtract.mins = x.mins - y.mins;
    subtract.secs = x.secs - y.secs;

    if(subtract.days < 0)
    {
        subtract.days = 0;                 
        subtract.hrs = 0;     
        subtract.mins = 0;
        subtract.secs = 0;              
    }        
    if(subtract.secs < 0)
    {    
        subtract.mins -= 1;
        subtract.secs = 60 + (x.secs - y.secs);   
    }
    if(subtract.mins < 0)
    {
        subtract.hrs -= 1;
        subtract.mins = 60 + (x.mins - y.mins);
    }
    if(subtract.hrs < 0)
    {               
        subtract.days -= 1;  
        subtract.hrs = 24 + (x.hrs - y.hrs);
    }
    else             
    {
        subtract.days;
        subtract.hrs;        
        subtract.mins;
        subtract.secs;
    }
}

[LB]

The fact that it returns anything at all is amazing. You have no return statement.

Please do not post more than once:
http://www.cplusplus.com/forum/general/157166/

[UGAman22]

I forgot to include my return statement. My bad. it's in my normal code. But I wouldn't normally do this, but I really need help on this..