How to show Last Time of System Booted
# run show system uptime
Current time: 2014-12-11 14:35:32 BDT
System booted: 2013-09-11 18:12:54 BDT (65w0d 20:22 ago)
Protocols started: 2013-09-11 18:14:41 BDT (65w0d 20:20 ago)
Last configured: 2014-12-11 13:17:08 BDT (01:18:24 ago) by level3
2:35PM up 455 days, 20:23, 3 users, load averages: 0.03, 0.09, 0.11
Here you can see the Current Date and Time.
Last Time of System Booted
Last Time of Protocols started
Last Time of configured