You can use System Manager to manage the cluster time.
Managing the cluster time (cluster administrators only)
Problems can occur when the cluster time is inaccurate. Although Data ONTAP enables you to manually set the time zone, date, and time on the cluster, you should configure the Network Time Protocol (NTP) servers to synchronize the cluster time.
Date and Time window
The Date and Time window enables you to view the current date and time settings for your storage system and modify the settings when required.