When John Glenn went into space and became the first American to orbit Earth, the only piece of technology he chose to wear other than the space suit itself, was a 12 hour stopwatch. While orbiting Earth, John Glenn crossed time zones every 20 minutes. Tracking stations across the globe synchronized their clocks with Glenn’s stopwatch creating a new time zone out of necessity. Set your own Mission Elapsed Time (MET) with Time Since Launch.
Along side this webapp is an ongoing project to build a physical long scale stopwatch built to last at least 100 years. You can follow some of the progress here. http://timefromlaunch.tumblr.com/