时间计算相关方法

<?php
    date_default_timezone_set(‘PRC‘); //默认时区
    echo "今天:",date("Y-m-d",time()),"\n";
    echo "今天:",date("Y-m-d",strtotime("18 june 2008")),"\n";
    echo "昨天:",date("Y-m-d",strtotime("-1 day")),"\n";
    echo "明天:",date("Y-m-d",strtotime("+1 day")),"\n";
    echo "一周后:",date("Y-m-d",strtotime("+1 week")),"\n";
    echo "一周零两天四小时两秒后:",date("Y-m-d G:H:s",strtotime("+1 week 2 days 4 hours 2 seconds")), "\n";
    echo "下个星期四:",date("Y-m-d",strtotime("next Thursday")),"\n";
    echo "上个周一:".date("Y-m-d",strtotime("last Monday"))."\n";
    echo "一个月前:".date("Y-m-d",strtotime("last month"))."\n";
    echo "一个月后:".date("Y-m-d",strtotime("+1 month"))."\n";
    echo "十年后:".date("Y-m-d",strtotime("+10 year"))."\n";
?>

今天:2017-11-06
今天:2008-06-18
昨天:2017-11-05
明天:2017-11-07
一周后:2017-11-13
一周零两天四小时两秒后:2017-11-15 22:22:42
下个星期四:2017-11-09
上个周一:2017-10-30
一个月前:2017-10-06
一个月后:2017-12-06
十年后:2027-11-06

<?php
    // 默认时区
    date_default_timezone_set(‘PRC‘);
     
    echo "今天: ", date(‘Y-m-d H:i:s‘), "\n";       // 输出当前时间
    echo "明天: ", date(‘Y-m-d H:i:s‘, strtotime(‘+1 day‘)), "\n";        // 输出明天时间
     
    //strtotime 可以接受第二个参数，类型timestamp为指定日期
    echo date(‘Y-m-d H:i:s‘, strtotime ("+1 day", strtotime(‘2017-11-11‘))), "\n";
     
     
    // 这里+1 day 可以修改参数1为任何想需要的数 
    // day也可以改成year（年）month（月）hour（小时）minute（分）second（秒）
    echo date(‘Y-m-d H:i:s‘, strtotime("+1 day +1 hour +1 minute")), "\n";
?>

今天: 2017-11-06 18:58:04
明天: 2017-11-07 18:58:04
2017-11-12 00:00:00
2017-11-07 19:59:04

 echo date("Y-m-d H:i:s"), "\n";
 
    // 日期天数相加函数
    echo date(‘Y-m-d‘, strtotime(‘+1 day‘, strtotime(‘2016-09-12‘))), "\n\n";
 
    echo strtotime(‘2016-09-12‘), "\n";
    echo date("Y-m-d", ‘1473609600‘), "\n";
    echo date("Y-m-d", ‘1573609600‘), "\n";
 
    // 日期天数相加函数
    $d = "2016-09-12 10:12:20";
    echo date("Y-m-d", strtotime("$d   +1   day")), "\n\n";  
 
    // 把日期转换成时间截
    function date2time($d){
        $year=((int)substr("$d",0,4));  //取得年份
        $month=((int)substr("$d",5,2)); //取得月份
        $day=((int)substr("$d",8,2));   //取得几号
        return mktime(0,0,0,$month,$day,$year);
    }
    echo date2time("2016-09-12"), "\n\n";
 
    $date_1="2066-09-12";
    $date_2="2016-09-12";
    $Date_List_a1=explode("-",$date_1);
    $Date_List_a2=explode("-",$date_2);
    $d1=mktime(0,0,0,$Date_List_a1[1],$Date_List_a1[2],$Date_List_a1[0]);
    $d2=mktime(0,0,0,$Date_List_a2[1],$Date_List_a2[2],$Date_List_a2[0]);
    $Days=round(($d1-$d2)/3600/24);
    echo "$date_2 -> $date_1 相差: $Days 天", "\n";

2017-11-06 19:13:02
2016-09-13
 
1473609600
2016-09-12
2019-11-13
2016-09-13
 
1473609600
 
2066-09-12 -> 2016-09-12 相差: 18262 天

$aaa = "18:00";
$bbb = 20;
$ddd = date("H:i",strtotime("$aaa + $bbb minute"));
echo $ddd;