Hello.

open Unix

let _ =
   let curr_time = time () in
   let curr_tm = gmtime curr_time in
   let new_time, _ = mktime {curr_tm with tm_hour = curr_tm.tm_hour+1} in
   let diff = new_time -. curr_time in
      Printf.printf "%f\n%f\n%f\n"
	 curr_time
	 new_time
	 diff


gives an negative result -7200.000000. Why?