Yes, text-based communication is inherently tough, since meaning is conveyed through more than just the words. But you just can't get your questions in front of a better audience than this one.
Thanks for attaching the code. Unfortunately, you make use of a number of subVIs that I don't have, including some that I could probably get by installing a driver (FieldPoint), and some that appear to be your own creations (make data string.vi and Seconds_to_Elapsed_Time_String.vi). Next time, when you're sharing code that uses subVIs of your own design, you can make sure to include them by choosing File >> Save with Options, and choosing "Development Distribution." That will make a library that includes the custom subVIs.
I could still open your main VI and see the general outline, and that's probably enough. The fact is that presenting a real-time chart of data with a variable sampling rate is difficult (mostly because it's potentially very memory-intensive), and I don't think there's a solution in the Express VI palette. In fact, I think it's best to refer back to my last post and suggest that you make friends with the the "XY Chart Buffer.vi" that ships with LabVIEW. (Help >> Find Examples, and search for xy)
This is a difficult example for several reasons, but it shows how to effectively manage variable-time chart data by using one instance of a reentrant subVI for each channel of data that you are plotting. What you would end up with if you expanded your VI to use this approach is 8 instances of the "XY Chart Buffer" subVI, with all 8 outputs built into an array that feeds into your XY Graph.
It may be time to reconsider whether you need to solve this problem right now, or whether a simple waveform chart with a fixed sampling period will give your operators a good enough sense of the shape of the data over the course of a day. You can always do what you suggest, and read the data into a graph from file if an operator wants to take a closer look with more exact timing information.
Some ideas,
John