The Fleet Sync Interval is the frequency at which CoPilot checks for any updates made by the fleet administrator—for as long as the CoPilot app remains open on the device. By default, the sync interval is set to 6 hours. In a Configuration Profile, that interval can be increased in half-hour increments, up to 24 hours, or down to 3 hours. 

Account Manager also syncs automatically each time CoPilot is opened on a device after it had been closed. This sync at launch restarts the timer for the sync interval. (So, for example, if the Fleet Sync Interval were set to 6 hours, the next sync would be 6 hours later—as long as CoPilot remains open.)