Get previous month's statistics as csv/tsv (not xml/json)

Is it normal that for method=Referers.getRefererType

&date=previous1&period=month&format=xml (same for format=json)
works, but
&date=previous1&period=month&format=tsv (same for format=csv)
gives the following error:


Error: Date format must be: YYYY-MM-DD, or 'today' or 'yesterday' or any keyword supported by the strtotime function (see http://php.net/strtotime for more information)

I would like to grab the previous month’s statistics but not in xml but csv/tsv format.

it looks like a “missing feature” - Can you please create a bug report: http://dev.piwik.org/trac

[quote=matt]
it looks like a “missing feature” - Can you please create a bug report: http://dev.piwik.org/trac[/quote]

ok, here it is: Support for date=previousX for csv/tsv format in Analytics API · Issue #3412 · matomo-org/matomo · GitHub
I reported it as a bug, not a feature request, since the API documentation as it is suggests that this should actually be working.