Submit Rainfall Total
It is prefered that totals are measured at 9AM each day, but if this is not possible just submit a daily total measured at any time. However a measurement taken at the same time each day is best. Select the closest hour in the time field. Submitting a new daily total for a day for which you've already submitted an earlier total will automatically overwrite the earlier total.
You can also setup a script to automatically submit your totals from an automatic rain gauge or weather station. A simple HTTP GET request with the data to http://qldstorms.com/rainfall.php. The fields are username, password, date(e.g. 2006-12-26), time(e.g. 09:00:00), and rainfall(mm).