Convert Date time output to TimeStamp for macros in Javascript webpart

Hi There, I searched the Kentico documentation for Macros and the forums with no luck. I am embedding javascript code in a portal Masterpage of our current project for a third party vendor that requires some logged-in user information and I am feeding the data to javascript via macros. From the code inserted in the in-line script of the javascript web part the output is as follows:Code: user : {% CurrentUser.UserActivationDate #%}Output: user : 8/1/2016 1:31:21 PM However I need as output the number of seconds since 1/1/1970 to be sent to this third party vendor. How can I convert the resulting value to Unix timestamp using macros?Thank you very much for your help!