Better to sync time only at night

[0xCAFEDECAF]

SolarMeter/Solarmeter.ino

Line 138 in 8f2cf97

if(lastHour == 2 || lastHour == 14)

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.