This object identifies the start of an eMTA maintenance window. A maintenance window is a period of time during which the ISP may perform network maintenance operations and network outages or software resets may occur. During a maintenance window, the eMTA will maintain the line voltage of an MTA regardless of CM resets, MTA resets, or RF losses. If any of these conditions occurs or persists outside of the scheduled maintenance window then the line voltage will be dropped unless the corresponding bit for the condition in question is set in the emtaMaintenanceControlMask MIB. If this object has never been set, it will have the value of midnight, January 1, 1970. Note that the time value used here is the local time as known by the device, as opposed to UTC. Also note that the value of this object will persist across a system reboot.