With IPHost Network Monitor you can run simple snmp requests against a D-Link device in your network.
swClockLostOnReboot
Switch Clock Lost On Reboot
1.3.6.1.4.1.171.12.10.3
Indication of whether the system can preserve knowledge of current date and time across a system reboot. A value of 'true' indicates the clock must be reset from some external source each time the system reboots. A value of 'false' indicates the system has the ability to keep time across reboots.
Back to DLINK-TIME-MIB MIB page.
IPHost Network monitor allows you to monitor swClockLostOnReboot on D-Link device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring D-Link access points right now.