On every site, we have "quick doc of API"
example of first line which manages date request: Actions.getActions (idSite, period, date, expanded = _, idSubtable =_) [ Example in XML, PHP, Json, Csv, Basic html , RSS of the last 10 days, 5 weeks, XML of the last 10 days ]
10 days, 5 weeks or last 10 days spoken in URL of yesterday :-X
choosen priority is major because it is a little annoying ;)
It appears you've disabled anonymous viewing of your piwik sites, i.e., in Settings => Users, you've set "anonymous" to "no access".
Otherwise, this is working correctly in 0.2.28 whether logged in or out.
p.s. If you don't want to see the "API" link, edit core/SmartyPlugins/function.assignTopBar.php.
10 days is not yesterday ;)
Thanks for report. Fixed in