php根据月份获取月份的起始时间和结束时间

//根据月份获取该月份的开始时间和结束时间
$timestamp = strtotime( $date );
$start_time = date( 'Y-m-1 00:00:00', $timestamp );
$mdays = date( 't', $timestamp );
$end_time = date( 'Y-m-' . $mdays . ' 23:59:59', $timestamp );


//获取上个月的第一天和最后一天的日期
$m_statetime = date('Y-m-01 00:00:00',strtotime('-1 month'));
 $m_endtime = date("Y-m-d 23:59:59", strtotime(-date('d').'day'));