Constructs an array of AM and PM options.
bool $required: (optional) If FALSE, the returned array will include a blank value. Defaults to FALSE.
array An array of AM and PM options.
public static function ampm($required = FALSE) {
$none = array(
'' => '',
);
$ampm = array(
'am' => t('am', array(), array(
'context' => 'ampm',
)),
'pm' => t('pm', array(), array(
'context' => 'ampm',
)),
);
return !$required ? $none + $ampm : $ampm;
}