Daily reset Time
From WeatherWiki
Daily Reset Time
Purpose: To insure your station's observations conform with international agreements for start and end of the day.
Daily reset time
You can choose either midnight reset (default) or 9am reset (used in Australia and New Zealand).
See under setup, values reset time option. At either midnight or 9am the daily high/low data will be reset, and yesterday rain will be set. Also, you can fine tune reset times if you need to, under setup, Display units options. I.e for hour to reset daily high/low values (temperature, wind), and hour to reset daily rain (e.g 1600 for 4pm) and month to reset the yearly rain (to match your rain season).