NetApp
7-mode/HA pair/V-Series : Configuration : System Tools : DateTime : Understanding date and time management : Guidelines for setting system date and time

Guidelines for setting system date and time
Keeping the system date and time correct is important to ensure that the storage system can service requests correctly.
To automatically keep your storage system time synchronized, you need the name of at least one time server. For best results, supply the name of more than one time server in case one becomes unavailable.
There are two protocols you can use for time synchronization: SNTP and rdate. SNTP (Simple Network Time Protocol) is more accurate; therefore, it is the preferred protocol.
If you can't access an SNTP server, you can use rdate. Many UNIX servers can function as an rdate server; see your system administrator to set up or identify an rdate server in your environment.
Configuration > System Tools > Date/Time/Timezone
The Date/Time/Timezone window provides a location to view the current date and time settings for your storage system. You can also change your system's date and time settings.
Command buttons
Edit
Opens the Edit Date Time Settings dialog box. You can use this dialog box to manually set the date, time, and time zone for your storage system.
Refresh
Updates the information in the window.