A method for operating cycle-oriented control software for controlling processes, wherein the software executes within a runtime environment on a computer system and uses two independent time bases: a first time base derived from a hardware timer, and a second time base provided by a another timer is transmitted via a network communication, and the second time base is provided via telegrams with time stamps, where a receive routine assigns time stamps to a receipt time and stores them in a buffer, an evaluation routine recognizes and compensates interrupts that disrupt the safe time base, the past values of the first time base are stored in a cyclical buffer that an interrupt handler periodically updates, the evaluation routine checks the time differences between the telegrams and corrects the second time base if required, such that reliable and safe time measurement are ensured, even in the event of system management interrupts.