Documentation for method
posix assembled from the following types:
method posix(Bool: = False --> Int)
Returns the date and time as a POSIX/UNIX timestamp (seconds since the Epoch, 1st January 1970 UTC).
DateTime object will be treated as if the time zone offset is zero.
say DateTime.new('2015-12-24T12:23:00Z').posix; # OUTPUT: «1450959780␤»