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Version 2.4.2Changelog

Firebase.ServerValue.TIMESTAMP

// Record the current time immediately, and queue an event to
// record the time at which the user disconnects.
var sessionsRef = new Firebase('https://samplechat.firebaseio-demo.com/sessions/');
var mySessionRef = sessionsRef.push();
mySessionRef.onDisconnect().update({ endedAt: Firebase.ServerValue.TIMESTAMP });
mySessionRef.update({ startedAt: Firebase.ServerValue.TIMESTAMP });