let utime_stamp =
   let old = ref 0.0 in
   fun msg -> 
      let times = Unix.times () in
      let stamp = times.Unix.tms_utime in
      let lap = stamp -. !old in
      Printf.printf "UTIME STAMP (%s): %f (%f)\n" msg stamp lap; flush stdout;
      old := stamp

let gmtime msg =
   let gmt = Unix.gmtime (Unix.time ()) in
   let yy = gmt.Unix.tm_year + 1900 in
   let mm = gmt.Unix.tm_mon in
   let dd = gmt.Unix.tm_mday in
   let h = gmt.Unix.tm_hour in
   let m = gmt.Unix.tm_min in
   let s = gmt.Unix.tm_sec in
   Printf.printf "UTC TIME STAMP (%s): %u/%u/%u %u:%u:%u\n" 
      msg yy mm dd h m s;
   flush stdout