  The design and performance of the GPS Timing and Control (GTC) System of the
High Altitude Water Cerenkov (HAWC) gamma ray observatory is described. The GTC
system provides a GPS synchronized absolute timestamp, with an accuracy better
than 1$\mu$s, for each recorded event in HAWC. In order to avoid any slack
between the recorded data and the timestamp, timestamps are injected to the
main data acquisition (DAQ) system after the Front-end Electronic Boards
(FEBs). When HAWC is completed, the HAWC main DAQ will use 10 time to digital
converters (TDCs). In order to keep all the TDCs in sync, the GTC system
provides a synchronized clock signal, coordinated trigger signal, and control
signals to all TDCs.
