Description:
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strftime is not showing the correct time zone as set by date_default_timezone_set

Please note strftime reflects the correct time for the new time zone setting, but not the correct time zone.

Reproduce code:
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<?php
  
 error_reporting(E_ALL);

 $before = strftime('%H:%M %z');
  
 date_default_timezone_set('America/New_York');

 $after = strftime('%H:%M %z');
  
 echo("date('e'): ". date('e'). ", strftime('%z'): ". strftime('%z'));

 echo ", strftime('%H:%M %z') before: $before, strftime('%H:%M %z') after: $after";
  
?> 

Expected result:
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date('e'): America/New_York, strftime('%z'): Eastern Daylight Time, strftime('%H:%M %z') before: 05:21 Eastern Daylight Time, strftime('%H:%M %z') after: 06:21 Eastern Daylight Time

Actual result:
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date('e'): America/New_York, strftime('%z'): Central Daylight Time, strftime('%H:%M %z') before: 05:21 Central Daylight Time, strftime('%H:%M %z') after: 06:21 Central Daylight Time

// note: on my setup Central Daylight Time would be expected if  date_default_timezone_set had not been used