上個月的月初和月末

/**
 * @param $date
 * @return array上個月的月初和月末
 */
public function GetlastMonthDays($date){
    $timestamp=strtotime($date);
    $firstday=date('Y-m-d',strtotime(date('Y',$timestamp).'-'.(date('m',$timestamp)-1).'-01'));
    $lastday=date('Y-m-d',strtotime("$firstday +1 month -1 day"));
    return ['start_last_month'=>$firstday,'end_last_month'=>$lastday];
}