PHP获取上个月第一天及最后一天

echo date('Y-m-01', strtotime('-1 month'));
echo "<br/>";
echo date('Y-m-t', strtotime('-1 month'));
echo "<br/>";

$BeginDate=date('Y-m-01', strtotime(date("Y-m-d")));
echo $BeginDate;
echo "<br/>";
echo date('Y-m-d', strtotime("$BeginDate +1 month -1 day"));
echo "<br/>";

echo " 本月共有:".date("t")."天";
echo " 当前年份".date('Y');
echo " 当前月份".date('m');
echo " 当前几号".date('d');
echo "<br/>";

function getthemonth($date)//$date的格式是yyyy-mm-dd{
$firstday = date('Y-m-01', strtotime($date));
$lastday = date('Y-m-d', strtotime("$firstday +1 month -1 day"));
return array($firstday,$lastday);
}
$today = date("Y-m-d");
$day=getthemonth($today);
echo "当月的第一天: ".$day[0]." 当月的最后一天: ".$day[1];
echo "<br/>";