The trick is that the last day of the month is the day before the first day of next month. So here's an example solution with Date::Manip: 

use Date::Manip; 
$input = "June 2006"; 
# these also work:
#$input = "2006 june"; 
#$input = "today"; 
#$input = "June 2006"; 
$thismonth = UnixDate($input, "%B %Y"); 
$lastofmonth = DateCalc($thismonth, "+1 month -1 day");
$dow_lastofmonth = UnixDate($lastofmonth, "%A\n"); 
print $dow_lastofmonth;

[download]
This prints Friday.

In reply to Re: Determining the dayname for the last day of any given month by ambrus
in thread Determining the dayname for the last day of any given month by McDarren

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