switch ($exchange_time) {

    case 1 : // 本月

    // 本月起始時(shí)間:

    $begin_time = date ( "Y-m-d H:i:s", mktime ( 0, 0, 0, date ( "m" ), 1, date ( "Y" ) ) );

    $end_time = date ( "Y-m-d H:i:s", mktime ( 23, 59, 59, date ( "m" ), date ( "t" ), date ( "Y" ) ) );

    break;

    case 2 : // 上個(gè)月

    // 上個(gè)月的起始時(shí)間:

    $begin_time = date('Y-m-01 00:00:00',strtotime('-1 month'));

    $end_time = date("Y-m-d 23:59:59", strtotime(-date('d').'day'));

    break;

    case 3 : // 上上個(gè)月

    $begin_time =  date("Y-m-d H:i:s",mktime(0, 0 , 0,date("m")-2,1,date("Y")));

    $end_time =  date("Y-m-d H:i:s",mktime(23,59,59,date("m")-1 ,0,date("Y")));

    break;

    }


    echo date("Ymd",strtotime("now")),"\n";

    echo date("Ymd",strtotime("-1 week Monday")),"\n";

    echo date("Ymd",strtotime("-1 week Sunday")),"\n";

    echo date("Ymd",strtotime("+0 week Monday")),"\n";

    echo date("Ymd",strtotime("+0 week Sunday")),"\n";

 

    echo "*********第幾個(gè)月:";

    echo date('n');

    echo "*********本周周幾:";

    echo date("w");

    echo "*********本月天數(shù):";

    echo date("t");

    echo "*********";

 

    echo '<br>上周起始時(shí)間:<br>';

    echo date("Y-m-d H:i:s",mktime(0, 0 , 0,date("m"),date("d")-date("w")+1-7,date("Y"))),"\n";

    echo date("Y-m-d H:i:s",mktime(23,59,59,date("m"),date("d")-date("w")+7-7,date("Y"))),"\n";

    echo '<br>本周起始時(shí)間:<br>';

    echo date("Y-m-d H:i:s",mktime(0, 0 , 0,date("m"),date("d")-date("w")+1,date("Y"))),"\n";

    echo date("Y-m-d H:i:s",mktime(23,59,59,date("m"),date("d")-date("w")+7,date("Y"))),"\n";

 

    echo '<br>上月起始時(shí)間:<br>';

    echo date("Y-m-d H:i:s",mktime(0, 0 , 0,date("m")-1,1,date("Y"))),"\n";

    echo date("Y-m-d H:i:s",mktime(23,59,59,date("m") ,0,date("Y"))),"\n";

    echo '<br>本月起始時(shí)間:<br>';

    echo date("Y-m-d H:i:s",mktime(0, 0 , 0,date("m"),1,date("Y"))),"\n";

    echo date("Y-m-d H:i:s",mktime(23,59,59,date("m"),date("t"),date("Y"))),"\n";

 

    $season= ceil((date('n'))/3);//當(dāng)月是第幾季度

    echo '<br>本季度起始時(shí)間:<br>';

    echo date('Y-m-d H:i:s',mktime(0, 0, 0,$season*3-3+1,1,date('Y'))),"\n";

    echo date('Y-m-d H:i:s',mktime(23,59,59,$season*3,date('t',mktime(0, 0 , 0,$season*3,1,date("Y"))),date('Y'))),"\n";

 

    $season= ceil((date('n'))/3)-1;//上季度是第幾季度

    echo '<br>上季度起始時(shí)間:<br>';

    echo date('Y-m-d H:i:s',mktime(0, 0, 0,$season*3-3+1,1,date('Y'))),"\n";

    echo date('Y-m-d H:i:s',mktime(23,59,59,$season*3,date('t',mktime(0, 0 , 0,$seas））