Time programmed events are quite common in gas chromatographic (GC) analyses, such as time programmed valve switching tasks prior to GC sampling. Also GC valve or device switching tasks during the analysis sequence are examples of these events. As chromatography data systems and time tables cannot control all time programmed events, Da Vinci Laboratory Solutions (DVLS) has developed Time Scheduler (TimeS): a software solution that automates the switching of relays, valves and devices prior to, during and after the actual run. It also functions as an external sequencer.