Preferrably do time update only when no sun is shining. A time shift can distort the "average" output of pvoutput: if the current period becomes (let's say) 12 minutes instead of 10 due to a 2 minute clock backwards setting, the average may be above the peak value, that is very ugly.
https://github.com/harold65/SolarMeter/blob/8f2cf97f13b269b32c362e6a9be9c3d1aeaded7b/Solarmeter.ino#L138
Preferrably do time update only when no sun is shining. A time shift can distort the "average" output of pvoutput: if the current period becomes (let's say) 12 minutes instead of 10 due to a 2 minute clock backwards setting, the average may be above the peak value, that is very ugly.