Dear Franco,

To change the start time, you can create restrictions(Settings->Restrictions). If you create a program or restriction, Netro will strictly follow the watering time and duration. You can also go to Settings->Preferences to set your preferred watering time. However, Netro will try to water during your preferred time. If Netro believes your watering is not enough, it will still water your zones regardless of you preferred watering time. 

Thanks,

Netro Support