Get Real Time - Not Device Set Time in android
You need to use the NTP (Network Time Protocol) protocol:
Here is some code I found somewhere else... and I am using it. This uses the Apache Commons library, which can be installed using Gradle (adding a dependency on commons-net:commons-net:3.6
)
If you need a list of time servers, check: http://tf.nist.gov/service/time-servers.html
Here is some Java Code for you to use:
public class TimeLookup { public static final String TIME_SERVER = "time-a.nist.gov"; public static void main(String[] args) throws Exception { NTPUDPClient timeClient = new NTPUDPClient(); InetAddress inetAddress = InetAddress.getByName(TIME_SERVER); TimeInfo timeInfo = timeClient.getTime(inetAddress); long returnTime = timeInfo.getReturnTime(); Date time = new Date(returnTime); System.out.println("Time from " + TIME_SERVER + ": " + time); }}
Note the Android code must run on the background thread and include gradle dependency:
implementation 'commons-net:commons-net:3.6'
There is no Android API to get you such a time. The user can always change the device time, nothing you can do about that.
Your best bet would be to run a server with a webservice, from which you can get the time. Since you control the server, you can try to ensure it returns the correct time.