I am working on pulling together 'Introducing Piwik 1.0' - a complete manual for new users. #1164
I have run across one thing I just cannot get my head around: the date range picker. GA has this really nice, quite intuitive date picker that I'm sure everyone's seen.
As far as I can tell, the only things you can pick with Piwik's is one complete day, week, month or year at a time? If that is the case then I think it's fairly critical to at least have a start and end picker, or even better something smooth like GA's before 1.0.
If that's not the case, and I'm just being thick, then please can someone tell me how to do it so I can put it in the manual?!
Integrate open source Date Slider in Piwik (After 1.0)
It is a known Piwik limitation that reports are only processed on weeks/months and years. See the feature request for custom date ranges: #572