PHP, how to convert Int value to Week days

function binToWeekdays($binvalue) {
  $decvalue = bindec($binvalue);
  $weekdays = array();
  if($decvalue & 1 << 1){
    $weekdays[] = 'Mon';
  }
  if($decvalue & 1 << 2){
    $weekdays[] = 'Tue';
  }
  if($decvalue & 1 << 3){
    $weekdays[] = 'Wed';
  }
  if($decvalue & 1 << 4){
    $weekdays[] = 'Thu';
  }
  if($decvalue & 1 << 5){
    $weekdays[] = 'Fri';
  }
  if($decvalue & 1 << 6){
    $weekdays[] = 'Sat';
  }
  if($decvalue & 1 << 0){
    $weekdays[] = 'Sun';
  }
  return implode(', ', $weekdays);
}

echo binToWeekdays('1100010') . "<br />\n"; // => Mon, Fri, Sat
echo binToWeekdays('11') . "<br />\n"; // =>  Mon, Sun

function binToWeekdays($binvalue, $map) {
    $decvalue = bindec($binvalue);
    $weekdays = [];
    
    foreach($map as $day => $exp){
        if (($decvalue & (1 << $exp)) != 0) {
            $weekdays[] = $day;
        }
    }
    return implode(', ', $weekdays);
}

// with sunday = 0
$map = [
    'Sun' => 0,'Mon' => 1,'Tue' => 2,
    'Wed' => 3,'Thu' => 4,'Fri' => 5,'Sat' => 6,
];  

echo binToWeekdays('1100010', $map) . "<br />\n"; // => Mon, Fri, Sat
echo binToWeekdays('11', $map) . "<br />\n"; // =>  Mon, Sun

// with monday = 0
$map = [
    'Mon' => 0,'Tue' => 1,'Wed' => 2,
    'Thu' => 3,'Fri' => 4,'Sat' => 5,'Sun' => 6,
];  

echo binToWeekdays('1100010', $map) . "<br />\n"; // => Tue, Sat, Sun
echo binToWeekdays('11', $map) . "<br />\n"; // =>  Mon, Tue

str_pad(1,7,"0",STR_PAD_LEFT)

function binToWeekdays($binvalue) {

    $binvalue = str_pad($binvalue, 7, "0", STR_PAD_LEFT);
    $array_week = array_reverse(str_split($binvalue));

    $weekdays = '';

    if ($array_week[1] == 1) {
        $weekdays .= 'Mon, ';
    }
    if ($array_week[2] == 1) {
        $weekdays .= 'Tue, ';
    }
    if ($array_week[3] == 1) {
        $weekdays .= 'Wed, ';
    }
    if ($array_week[4] == 1) {
        $weekdays .= 'Thu, ';
    }
    if ($array_week[5] == 1) {
        $weekdays .= 'Fri, ';
    }
    if ($array_week[6] == 1) {
        $weekdays .= 'Sat, ';
    }
    if ($array_week[0] == 1) {
        $weekdays .= 'Sun';
    }

    return $weekdays;

}

echo binToWeekdays('11');

Mon, Sun