(PHP 5.5.0, PECL >= 3.0.0a1)
IntlCalendar::setRepeatedWallTimeOption — Set behavior for handling repeating wall times at negative timezone offset transitions
Object oriented style
$wallTimeOption
   )Procedural style
   Sets the current strategy for dealing with wall times that are repeated
   whenever the clock is set back during dailight saving time end transitions.
   The default value is IntlCalendar::WALLTIME_LAST (take
   the post-DST instant). The other possible value is
   IntlCalendar::WALLTIME_FIRST (take the instant that
   occurs during DST).
  
This function requires ICU 4.9 or later.
calThe IntlCalendar resource.
wallTimeOption
      One of the constants IntlCalendar::WALLTIME_FIRST or
      IntlCalendar::WALLTIME_LAST.
     
   Returns TRUE on success. Failure can only happen due to invalid parameters.
  
See the example on IntlCalendar::getRepeatedWallTimeOption().