Allied Telesis AT-S63 - Manual (Page 70)

Chapter 3: Basic Switch Parameters
70 Section I: Basic Operations
The Last Delta option in the menu displays the last adjustment that
was applied to system time due to a drift in the system clock between
two successive queries to the SNTP server. This is a read only field.
Option U, Update System Time, allows you to prompt the switch to poll
the SNTP or NTP server for the current time and date. You can use
this selection to update the time and date immediately rather than wait
for the switch’s next polling period. This selection has no effect if you
set the date and time manually.
14. After making changes, type R until you return to the Main Menu. Then
type S to select Save Configuration Changes.