Sumit beat me to the punch. I know this is available as of 15.4 code not sure if it is in anything before that. Here's the section from the user guide
"Configuring the NTP Server/Client"
"An NTP server provides clock information to NTP or SNTP clients. You can configure an NTP server as"
"an NTP client to receive clock information from more reliable external NTP servers or a local clock. You can also build a hierarchical time distribution topology by using TCP/IP. The switch can work as both an NTP client and server at the same time to build a hierarchical clock distribution tree. This hierarchical structure eliminates the need for a centralized clock server and provides a highly available clock tree with minimal network load and overhead."
"• To configure an NTP server, use the following command:"
"configure ntp [server | peer] add [ip_address | host_name] {key keyid} {option"
"[burst | initial-burst]}"
"configure ntp restrict-list [add | delete] network {mask} [permit | deny]"
"• To delete an NTP server, use the following command:"
"configure ntp [server | peer] delete [ip_address | host_name]"
"• To display NTP server or client information, use the following commands:"
"show ntp"
"show ntp association [{ip_address} | {host_name}]"
"show ntp restrict-list {user | system | all}"
"show ntp sys-info"
"Managing the Switch"
"Basic"
Good luck
P