Cloud functions

Particle.syncTime()

Synchronize the time with the Particle Device Cloud. This happens automatically when the device connects to the Cloud. However, if your device runs continuously for a long time, you may want to synchronize once per day or so.

#define ONE_DAY_MILLIS (24 * 60 * 60 * 1000)
unsigned long lastSync = millis();

void loop() {
  if (millis() - lastSync > ONE_DAY_MILLIS) {
    // Request time synchronization from the Particle Device Cloud
    Particle.syncTime();
    lastSync = millis();
  }
}

Note that this function sends a request message to the Cloud and then returns. The time on the device will not be synchronized until some milliseconds later when the Cloud responds with the current time between calls to your loop. See Particle.syncTimeDone(), Particle.timeSyncedLast(), Time.isValid() and Particle.syncTimePending() for information on how to wait for request to be finished.

Synchronizing time does not consume Data Operations from your monthly or yearly quota. However, for cellular devices they do use cellular data, so unnecessary time synchronization can lead to increased data usage, which could result in hitting the monthly data limit for your account.

For more information about real-time clocks on Particle devices, see Learn more about real-time clocks.