If you use the DataVista Range flow card as the source for your progress bar, then you can override the displayed temperature with something custom. Like a combination of some text, the min/max temperature value and the timestamp.
My assumption is that the timestamp is available already as a data element. If not then an option would be to update a variable holding the latest min/max timestamp, and testing and (if necessary) updating that whenever the temperature changes (and at the start of a new day).
