set nowtime [clock seconds]
set happened "Fri, 06 Apr 2012 14:33:00 -0400"
set newtime [clock scan $happened]
puts "Last checked [expr {$nowtime-$newtime}] seconds ago"
c2V0IG5vd3RpbWUgW2Nsb2NrIHNlY29uZHNdCnNldCBoYXBwZW5lZCAiRnJpLCAwNiBBcHIgMjAxMiAxNDozMzowMCAtMDQwMCIKc2V0IG5ld3RpbWUgW2Nsb2NrIHNjYW4gJGhhcHBlbmVkXQpwdXRzICJMYXN0IGNoZWNrZWQgW2V4cHIgeyRub3d0aW1lLSRuZXd0aW1lfV0gc2Vjb25kcyBhZ28i