Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to report
a bug at http://bugs.php.net/how-to-report.php

Windows doesn\'t support all modifiers, see http://msdn.microsoft.com/en-us/library/az4se3k1(VS.71).aspx for the supported ones (and that link is in the manual at http://uk3.php.net/strftime .

Doh.

Seems that even the most recent MSDN docs 
(http://msdn.microsoft.com/en-us/library/az4se3k1(VS.100).aspx and 
http://msdn.microsoft.com/en-us/library/8kb3ddd4(VS.100).aspx) is out 
of date.

No mention of %p, yet it works.



<?php
error_reporting(0);

$a_Remaining = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
$a_Formats = array(
  'Day'                 => 'aAdejuw',
  'Week'                => 'UVW',
  'Month'               => 'bBhm',
  'Year'                => 'CgGyY',
  'Time'                => 'HIlMpPrRSTXzZ',
  'Time and Date Stamps'=> 'cDFsx',
  'Miscellaneous'       => 'nt%',
  'Unknown'             => &$a_Remaining
);

foreach($a_Formats as $s_Group => $s_GroupFormats) {
  echo $s_Group, PHP_EOL;
  foreach(range(0, strlen($s_GroupFormats) - 1) as $i_Format) {
    echo
      "\t{$s_GroupFormats[$i_Format]} : ",
      (!($s_Output = strftime('%' . $s_GroupFormats[$i_Format]))
        ? "\t\t\t[Unknown]"
        : $s_Output),
      PHP_EOL;
    $a_Remaining = str_replace($s_GroupFormats[$i_Format], '', 
$a_Remaining);
  }
}


outputs ...

Day
        a : Mon
        A : Monday
        d : 07
        e :                     [Unknown]
        j : 250
        u :                     [Unknown]
        w : 1
Week
        U : 36
        V :                     [Unknown]
        W : 36
Month
        b : Sep
        B : September
        h :                     [Unknown]
        m : 09
Year
        C :                     [Unknown]
        g :                     [Unknown]
        G :                     [Unknown]
        y : 09
        Y : 2009
Time
        H : 12
        I : 12
        l :                     [Unknown]
        M : 35
        p : PM
        P :                     [Unknown]
        r :                     [Unknown]
        R :                     [Unknown]
        S : 03
        T :                     [Unknown]
        X : 12:35:03
        z : GMT Standard Time
        Z : GMT Standard Time
Time and Date Stamps
        c : 09/07/09 12:35:03
        D :                     [Unknown]
        F :                     [Unknown]
        s :                     [Unknown]
        x : 09/07/09
Miscellaneous
        n :                     [Unknown]
        t :                     [Unknown]
        % : %
Unknown
        E :                     [Unknown]
        J :                     [Unknown]
        K :                     [Unknown]
        L :                     [Unknown]
        N :                     [Unknown]
        O :                     [Unknown]
        Q :                     [Unknown]
        f :                     [Unknown]
        i :                     [Unknown]
        k :                     [Unknown]
        o :                     [Unknown]
        q :                     [Unknown]
        v :                     [Unknown]


Thanks Derick. Next time I'll RTFM!

Link is wrong. PHP uses VC++ not VC.NET. See http://bugs.php.net/bug.php?id=49498

%p is correctly documented for the VC++ runtime reference.