As part of the RSView32 Resource kit there's a "Synchronise Time and Date" utility which you simply configure and then launch from an RSView32 command. (from memory its appstart synctad /s but there's a help file that goes with it)
All you're really doing is setting the words in the the S regigisters where the date/time is stored based on the system date/time tags in RSView. The utility is nice 'as it allows you to use any machine, PC or PLC, in the network as the master.