Can't store time over 9 hours and 10 minutes
Here's a hint: 32767 seconds is 9 hours, 6 minutes and 7 seconds.

What is the largest value that an int can hold?



EDIT: I can't add comments on this computer (old browser), so I have to respond to your question here.
time_t is an unsigned 32-bit value, but all of your input values are signed 16-bit values. When you take a product like 3600*10, you get a bit pattern of 1000110010100000, which is 36000 when interpreted as an unsigned value, but is -29536 when interpreted as a signed value.

When assigned to a time_t, the value is sign-extended to 32 bits, which makes it 11111111111111111000110010100000, which is 4294937760 when interpreted as an unsigned value.

If you want to write a statement like

time_t x = (hoursSet * 3600) + (minutesSet * 60);


you need to type-cast your input arguments to the correct type first:

time_t x = ((time_t)hoursSet * 3600) + ((time_t)minutesSet * 60);