In ASA, you can changing time using the clock set command:
asa(config)# clock set hh:mm:ss day MONTH year
i belive that No reboot is required after using this command.
Effects of changing the clock on the ASA:
This change can have a major impact on event correlation activities that are performed as part of normal operations troubleshooting and monitoring.
For security-related devices, where logs are captured, correlated, and stored for future reference, this time change could render them incorrect for situations where they need to be recalled to rebuild a sequence of events. The incorrect timestamps might not be an issue for events that get immediate action. However, in the future, these events would reference incorrect times.
Any device with time-based controls and activities, such as a AAA servers, Content Devices (CEs), cron jobs, and video streaming servers can be impacted and should be checked with the appropriate vendor.
