Output raw unix time from xen:date/datetime?

[CyberAP]

Is there any way to output a raw unix time from xen:date function?
I have a call {xen:datetime $user.last_activity, absolute} and need to get just a raw number instead of 11 Jul 2016 10:00.

 

[CyberAP]

Sorry, it was obvious, just use the variable itself: {$user.last_activity}.