I used this setup but I split it up in to two 12 hour blocks. Day shift and night shift. The original setup uses the GSV instruction for hours and some other instructions to know weather it is day shift or night shift. But it is all messed up. The internal clock was just a hour off on the processor. But the GSV instructions where way off.
There were problems with the Wallclock time updates on some of the earlier Compactlogix PLCs. Firmware updates supposedly fixed these problems, but you might still have a unit with the Version 16 or earlier firmware.
Welcome to the forum Mikey7121. The post you have resurrected is from 2015. I would advise you start a new thread explaining what you need, so your requirement can start as a blank slate.