echo date("Y-m-d",strtotime("now"));
echo "<br>";
echo date("Y-m-d",strtotime("-1 week Monday"));
echo "<br>";
echo date("Y-m-d",strtotime("-1 week Sunday"));
echo "<br>";
echo date("Y-m-d",strtotime("+0 week Monday"));
echo "<br>";
echo date("Y-m-d",strtotime("+0 week Sunday"));
echo "<br>";
echo "*********第几个月:";
echo date(‘n‘);
echo "<br>";
echo "*********本周周几:";
echo date("w");
echo "<br>";
echo "*********本月天数:";
echo date("t");
echo "<br>";
echo "*********";
echo ‘<br>上周起始时间:<br>‘;
echo date("Y-m-d H:i:s",mktime(0, 0 , 0,date("m"),date("d")-date("w")+1-7,date("Y")));
echo "<br>";
echo date("Y-m-d H:i:s",mktime(23,59,59,date("m"),date("d")-date("w")+7-7,date("Y")));
echo "<br>";
echo ‘<br>本周起始时间:<br>‘;
echo date("Y-m-d H:i:s",mktime(0, 0 , 0,date("m"),date("d")-date("w")+1,date("Y")));
echo "<br>";
echo date("Y-m-d H:i:s",mktime(23,59,59,date("m"),date("d")-date("w")+7,date("Y")));
echo "<br>";
//从第几周找出该周的开始日期和结束日期
$dayNumber = date(‘W‘) * 7;
$weekDayNumber = date("w", mktime(0, 0, 0, 1, $dayNumber, date("Y")));//当前周的第几天
$startNumber = $dayNumber - $weekDayNumber;
echo date("Y-m-d", mktime(0, 0, 0, 1, $startNumber + 1, date("Y")));//开始日期
echo "<br>";
echo date("Y-m-d", mktime(0, 0, 0, 1, $startNumber + 7, date("Y")));//结束日期
echo "<br>";
echo ‘<br>上月起始时间:<br>‘;
echo date("Y-m-d H:i:s",mktime(0, 0 , 0,date("m")-1,1,date("Y")));
echo "<br>";
echo date("Y-m-d H:i:s",mktime(23,59,59,date("m") ,0,date("Y")));
echo ‘<br>本月起始时间:<br>‘;
echo date("Y-m-d H:i:s",mktime(0, 0 , 0,date("m"),1,date("Y")));
echo "<br>";
echo date("Y-m-d H:i:s",mktime(23,59,59,date("m"),date("t"),date("Y")));
echo "<br>";
$season = ceil((date(‘n‘))/3);//当月是第几季度
echo ‘<br>本季度起始时间:<br>‘;
echo date(‘Y-m-d H:i:s‘, mktime(0, 0, 0,$season*3-3+1,1,date(‘Y‘)));
echo "<br>";
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‘)));
echo "<br>";
$season = ceil((date(‘n‘))/3)-1;//上季度是第几季度
echo ‘<br>上季度起始时间:<br>‘;
echo date(‘Y-m-d H:i:s‘, mktime(0, 0, 0,$season*3-3+1,1,date(‘Y‘)));
echo "<br>";
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‘)));