Print OrderOpenTime

 
When I try to Print the OrderOpenTime, it is displaying a 10 digit number which is not at all related to date. How can I convert this to real Date and time.
Please help...thanks in advance.

if(OrderSelect(OrderSymbol(), SELECT_BY_POS)==true)
Print("open time for the order ",OrderOpenTime());
else
Print("OrderSelect returned error of ",GetLastError());
 
TimeToStr()