A system, method and computer program product for performing a Perform Timing Facility (PTFF) instruction for steering a Time of Day (TOD) clock of the computer system for synchronizing the TOD clock with TOD clocks of other computer systems. The computer system comprises a memory; and, a processor in communications with the computer memory. The processor is capable of performing a PTFF instruction comprising: obtaining a function code specified in a first general register, the function code for identifying any one of a query function or a control function to be performed; obtaining, from a second general register, a memory address of a parameter block; responsive to the function code specifying a query function, storing timing information of the computer system in the parameter block according to the specified query function; responsive to the function code specifying a control function, using timing information obtained from the parameter block to perform the specified control function; and setting a condition code value indicating an outcome of the specified function.