title: How make time synchronization between android devices when lack access to GPS, GSM and Internet?
body: <p>I need to synchronize time between two or more android devices. But I don't need change local time, only knew different in time on different devices.</p>
  
  <p>I cannot assume that devices have access to GPS or GMS or even to Internet. The connection is made in intranet by WIFI.</p>
  
  <p>Is a API on Android which help me make this quick?  </p>
  
  <p>For connection I use Socket and ServerSocket classes.</p>
  
  <p>Update: I search API which help me to exchange data about time and synchronize it.</p>