Hi David,
To cancel the restriction, please go to schedule->tab the specific date (date with gray dot beneath is your restriction date), then tap on the specific restriction, it will give you the option to cancel the restriction.
Rain delay is to forbidden watering in the next following days after rain and it is one-time setting. If you want to save the settings, please go to settings->preferences -> rain -> days to skip.
Thanks,
Wency
Netro Support