After a drop in the internet connection followed by a disconnected network cable, I’m getting an an odd updated “-3589s ahead” appearing on the inputs on my emoncms.org page.
Having checked the time on the Pi is correct & searched though other posts who had this issue, it looks like @TrystanLea is my only hope… 
The graphs are correct, but show an hour behind if you click Day, but oddly I can scroll forward and there is more data there. The weather station data also has the same problem, but is posted from a different server which wasn’t disconnected.