i've got a weird issue with the first date from calendar entries showing up as the wrong day number and weekday. ie: instead of 01 Sunday it reads 001 Monday, but every other entry loads perfectly.
full code:
{exp:calendar:cal calendar_id="5057" date_range_start="{segment_3}-{segment_4}-01" pad_short_weeks="n" show_months="1"}
{display_each_month}
{display_each_day}
{if day_event_total > 0}<strong>{date format="%d %l"}</strong>{/if}
{events}
{event_start_date format="%g:%i %a"}<br />
{title}<br />
{/events}
{/display_each_day}
{/display_each_month}
{/exp:calendar:cal}
you can see it working here (with some additional inline formatting), in the right column under March Calendar
Update: to confuse things more, there is another monthly calendar on the site, from which i created the template above, which does not commit the same error. both have the same settings for PHP handling and use the exact same tags to generate the content.