'This function uses the node\'s launch_time to determine how many minutes
this instance has been running. You can mod (%) the return value with
60 to determine how many minutes into a billable hour this node has
been running.'

def _minutes_uptime(self, node):

    dt = utils.iso_to_datetime_tuple(node.launch_time)
    now = self.get_remote_time()
    timedelta = (now - dt)
    return (timedelta.seconds / 60)
