In Orbit Timing Calibration of the Hard X-Ray Detector on Board Suzaku

The hard X-ray detector (HXD) on board the X-ray satellite Suzaku is designed to have a good timing capability with a 61 $mu$s time resolution. In addition to detailed descriptions of the HXD timing system, results of in-orbit timing calibration and performance of the HXD are summarized. The relative accuracy of time measurements of the HXD event was confirmed to have an accuracy of $1.9times 10^{-9}$ s s$^{-1}$ per day, and the absolute timing was confirmed to be accurate to 360 $mu$s or better. The results were achieved mainly through observations of the Crab pulsar, including simultaneous ones with RXTE, INTEGRAL, and Swift.