Ok. Looks like it’s the AJAX timeout in main.js.php. When I increase the time out to 6000 it works (the timeout is set to 5000). The Firefox developer console shows the specific operation took 5413ms. Viewing the next day preview takes 4555ms I guess this explains why I could see the next day preview and not the current day. I’m guessing the time to include the current time marker on today’s preview chart is the difference between the two operations. When I check resources on my my web server (it’s a Belkin router) loading of that preview page takes me from an idle cpu to 80-95% utilization. So simply put, I think you’re taxing my router! I wonder how my router CPU (Broadcom BCM4716 chipset) compares to the RPi server…
Could we increase the timeout to 8 or 10 sec if you don’t see an obvious inefficiency in the code.