1. fixed a minor bug 2.suppress php date() warning 3. correct date format for linux date

src/camvc.php

@@ -345,12 +345,12 @@ function decodeGet ($encoded_get) {
             case "_time":
               $toRead["req_ts"]=$value; /// Request time stamp, as received. Will be used by sender
               $a=((float) $value)/1000;
-              if (abs(elphel_get_fpga_time()-$a) > 24*3600) break; // time already set
+              if (abs(elphel_get_fpga_time()-$a) < 24*3600) break; // time already set
             case "_stime":
               $toRead["req_ts"]=$value;
               $a=((float) $value)/1000;
               elphel_set_fpga_time ($a); // set FPGA time
-              exec("date -s ".date("mdHiY.s",(int)$a),$out,$ret); // set system time
+              exec("date -s ".@date("Y-m-d H:i:s.u",(int)$a),$out,$ret); // set system time
               exec("hwclock --systohc");
               break;
             case "imgsrv":