Updating to the latest firmware is a good idea. A good way to ensure the time and date stay correct is to set the camera to pull time from the network.
Access the camera's web server (http://cam's LAN ip address) and choose Setup --> Time and Date. Select "Synchronize with NTP server." You have two choices below that:
1. Set NTP server from DHCP (which is what I use to get time from my router)
2. Choose a specific NCP server such as ntp1.dlink.com
Save the settings and you won't have to worry about the time & date anymore.