calendar view: 27.10.13 appears twice, then all weekdays wrong

[testbird]

The calendar shows October 2013 with the 27th once as the 4th sunday, then again as monday in the next row (still colored with the weekend shade).

[testbird]

Oh bummer. Just noticed that all weekdays after the 27th october 2013 are wrong by one day.

[testbird]

Hello, I found this calendar bug only pops up if the following zafu is used, that shows a second calendar widget in the block.

Here is the zafu to experience the same 27.10.13 date twice:

<div id='cal' do='block'>
<r:void do='calendar' attr='date' size='large' tz='Europe/Berlin' select='posts where #{cal_start} <= date and date < #{cal_end} in section order by date asc, title asc'>
  <h3 do='header'>
    <a rel="nofollow" do='link' date='date.advance(:months => -1)' update='cal' t='img_prev_page'/>
    <r:date format='%B %Y'/>
    <a rel="nofollow" do='link' date='date.advance(:months => 1)' update='cal' t='img_next_page'/>
  </h3>
</r:void>

<r:void set_date='date.advance(:months => 1)'>

<r:void do='calendar' attr='date' size='large' tz='Europe/Berlin' select='posts where #{cal_start} <= date and date < #{cal_end} in section order by date asc, title asc'>
  <h3 do='header'>

    <r:date format='%B %Y'/>

  </h3>
</r:void>

</r:void>

</div>

[testbird]

Trial and error finally showed the error is caused by the option tz='Europe/Berlin' in the zafu code above.

On the 27.10.13 this timezone changes from "daylight saving" summertime to wintertime.

[testbird]

To avoid problems with those double (a/b) hours and skipped hours, maybe it is sufficient to use noon (12 o'clock) as reference for the days instead of the beginning 00:00 hour?