THE EXQUISITE PHOTOMETRY AND CONTINUOUS VIEWING CAPABILITY OF THE KEPLER SPACECRAFT MAKE IT POSSIBLE FOR THE FIRST TIME TO UNDERTAKE A COMPREHENSIVE INVESTIGATION OF PHOTOSPHERIC STELLAR ACTIVITY BY TRACKING THE SUBTLE BRIGHTNESS CHANGES AS STARSPOTS CROSS A STELLAR SURFACE. AS STARS AGE THEY LOSE ANGULAR MOMENTUM TO THEIR STELLAR WIND AND SPIN DOWN; BY TRACKING STARSPOTS A STAR'S ROTATION CAN BE MEASURED. THE RELATION BETWEEN STELLAR AGE MASS (OR SPECTRAL TYPE) AND ROTATION PERIOD CAN BE USED FOR GYROCHRONOLOGY I.E. FINDING A STAR'S AGE IF THE RELATION CAN BE SUITABLY CALIBRATED. WHILE SOME INFORMATION ON ROTATION PERIODS EXISTS FOR SPECTRAL TYPE F AND G STARS STARS YOUNGER THAN ABOUT 600 MILLION YEARS THERE IS ONLY LIMITED INFORMATION FOR OLDER AND COOLER STARS.THE PLAN IS TO DERIVE A NEW AGE/MASS/ROTATION PERIOD RELATION FOR COOL STARS OF SPECTRAL TYPE F G AND K USING ROTATION PERIODS OF SEVERAL GROUPS OF STARS IN THE KEPLER ARCHIVE. THE FOUNDATION FOR A NEW RELATION WILL BE THE STAR CLUSTERS IN THE KEPLER FIELD BUT THEY COVER ONLY A FEW AGES AND A SMALL RANGE IN SPECTRAL TYPE. THE PLAN WILL BE TO BUILD ON THE CLUSTER FOUNDATION WITH A NEW LIST OF WIDE BINARY AND COMMON PROPER MOTION STARS A SELECTION OF KEPLER PLANET SYSTEMS FOR WHICH AGES HAVE ALREADY BEEN DETERMINED WITH THE HELP OF GROUND-BASED SPECTROSCOPY AND MODELS AND SOME MAIN SEQUENCE STARS FOR WHICH AGES HAVE BEEN ESTIMATED WITH THE HELP OF KEPLER ASTEROSEISMOLOGY.WITH A WELL-DEFINED GYROCHRONOLOGY RELATION IT WILL BE POSSIBLE TO DERIVE RELIABLE AGES FOR MANY OF THE KEPLER PLANET CANDIDATES THAT ARE TOO FAINT TO BE EASILY ACCESSIBLE TO GROUND-BASED SPECTROSCOPY. IT WILL ALSO BE POSSIBLE TO DERIVE AGES FOR TENS OF THOUSANDS OF STARS IN THE KEPLER ARCHIVE ADDING TO THE VALUE OF THE ARCHIVE.