Here is a Demo that uses SNTP (Simple Network Time Protocol) to Sync and Set the time of the on-board Spinneret RTC (Real Time Clock). The W5100 is accessed in Indirect mode to open a socket in UDP mode to retrieve the SNTP data. The RTC is then set to the SNTP time and displayed using the PST (Parallax Serial Terminal)
Note2: A previous version used the W5100 in SPI mode, this version uses Indirect/Parallel mode. Not that it matters much for setting the RTC, I just thought it would be easier to transition into an HTML Web application already using the Indirect driver without loading another object.
"Irony hides in the deception of your current view of the situation" - Me ....
In other words, do not believe what you are told and what you immediately perceive until you find out the absolute truth for yourself from all possible angles.