/**Returns a relative timestamp in the form "seconds,milliseconds". Each
	 * segment is zero-padded to three digits, ensuring a consistent length of
	 * seven characters. The timestamp has no absolute meaning. It is merely the
	 * elapsed time since January 1, 1970 UT truncated at 999 seconds. Do not
	 * use this for production code, especially for mathematically determining
	 * the relative time between two events, since the counter will flip to zero
	 * roughly every 16 minutes.
         */