获取一周的第一个/最后一个日期 - Getting first / last date of the week

是否可以使用PHP的相对日期时间格式获得一周的第一个/最后一个日期?

I've try to do:

date_default_timezone_set('Europe/Amsterdam');
$date = new DateTime();
$date->modify('first day of this week'); // to get the current week's first date
echo $date->format('Y-m-d'); // outputs 2011-12-19
$date->modify('first day of week 50'); // to get the first date of any week by weeknumber
echo $date->format('Y-m-d'); // outputs 2011-12-18
$date->modify('last day of this week'); // to get the current week's last date
echo $date->format('Y-m-d'); // outputs 2011-12-17
$date->modify('last day of week 50'); // to get the last date of any week by weeknumber
echo $date->format('Y-m-d'); // outputs 2011-12-18

如你所见，它没有输出正确的日期。

根据文档，如果我是正确的，这应该是可能的。

我做错什么了吗?

编辑

我需要使用PHP的DateTime日期在遥远的未来。

现在变得更奇怪了。我又做了一些测试。

Windows PHP 5.3.3

2011-12-01
Warning: DateTime::modify() [datetime.modify]: Failed to parse time string (first day of week 50) at position 13 (w): The timezone could not be found in the database in C:'Users'Gerrie'Desktop'ph'Websites'Charts'www.charts.com'public'index.php on line 9
2011-12-01
2011-11-30
Warning: DateTime::modify() [datetime.modify]: Failed to parse time string (last day of week 50) at position 12 (w): The timezone could not be found in the database in C:'Users'Gerrie'Desktop'ph'Websites'Charts'www.charts.com'public'index.php on line 15
2011-11-30

Linux 5.3.8

我非常喜欢使用Carbon库，它使这类事情非常容易。例如:

use Carbon'Carbon;
$monday = Carbon::now()->startOfWeek()
$sunday = Carbon::now()->endOfWeek()

或者，如果你想把星期天作为一周的第一天:

use Carbon'Carbon;
Carbon::setWeekStartsAt(Carbon::SUNDAY);
Carbon::setWeekEndsAt(Carbon::SATURDAY);
$sunday = Carbon::now()->startOfWeek()
$saturday = Carbon::now()->endOfWeek()

根据文档，格式字符串"first day of"answers"last day of"只允许用于月，而不允许用于周。见http://www.php.net/manual/en/datetime.formats.relative.php

如果将week语句的第一天和最后一天结合起来，结果要么会使解析器出错，要么是您没有预料到的结果(通常是一个月的第一天或最后一天，而不是一个星期)。

你看到的Win和Linux之间的差异可能只是因为不同的错误报告设置。

要获取当前星期的第一天和最后一天，使用:

$date->modify('this week');
$date->modify('this week +6 days');

要获取第50周的第一天和最后一天，请使用:

$date->setISODate(2011, 50);
$date->setISODate(2011, 50, 7);

编辑:

如果想对绝对周数使用modify方法，则必须使用http://www.php.net/manual/en/datetime.formats.compound.php:

中定义的格式。

$date->modify('2011W50');
$date->modify('2011W50 +6 days');

如果一周的第一天是星期一

$date->modify('Monday this week');

else if第一天是星期天

$date->modify('Sunday this week');

因为在不同的国家，一周的第一天可能是星期一或星期天

这是我用来从获得一周的第一天和最后一天的任何日期。在这种情况下，星期一是一周的第一天…

$date = date('Y-m-d'); // you can put any date you want
$nbDay = date('N', strtotime($date));
$monday = new DateTime($date);
$sunday = new DateTime($date);
$monday->modify('-'.($nbDay-1).' days');
$sunday->modify('+'.(7-$nbDay).' days');

function getweek_first_last_date($date)
{
    $cur_date = strtotime($date); // Change to whatever date you need
    // Get the day of the week: Sunday = 0 to Saturday = 6
    $dotw = date('w', $cur_date);
    if($dotw>1)
    {
        $pre_monday  =  $cur_date-(($dotw-1)*24*60*60);
        $next_sunday = $cur_date+((7-$dotw)*24*60*60);
    }
    else if($dotw==1)
    {
        $pre_monday  = $cur_date;
        $next_sunday =  $cur_date+((7-$dotw)*24*60*60);
    }
    else if($dotw==0)
    {
        $pre_monday  =$cur_date -(6*24*60*60);;
        $next_sunday = $cur_date;
    }
    $date_array =   array();
    $date_array['start_date_of_week'] = $pre_monday;
    $date_array['end_date_of_week'] = $next_sunday;
    return $date_array;
}
$date = '2013-12-22';
getweek_first_last_date($date);

Output :
$array_of_week = Array
(
    [start_date_of_week] => 1387152000
    [end_date_of_week] => 1387670400
)
$start_date =date('d/m/Y', $array_of_week['start_date_of_week'])

<code>
function getlastweek_first_last_date()
{
   $cur_date = strtotime(date('Y-m-d')); // Change to whatever date you need
    // Get the day of the week: Sunday = 0 to Saturday = 6
    $previousweekcurdate  = $cur_date - (7*24*3600);
    $cur_date = $previousweekcurdate;
    $dotw = date('w', $cur_date);
    if($dotw>1)
    {
        $pre_sunday  =  $cur_date-(($dotw-1)*24*60*60) - (24*60*60);
        $next_satday = $cur_date+((7-$dotw)*24*60*60)- (24*60*60);
    }
    else if($dotw==1)
    {
        $pre_sunday  = $cur_date- (24*60*60);
        $next_satday =  $cur_date+((7-$dotw)*24*60*60)- (24*60*60);
    }
    else if($dotw==0)
    {
        $pre_sunday  =$cur_date -(6*24*60*60)- (24*60*60);
        $next_satday = $cur_date- (24*60*60);
    }
    $pre_sunday = date('Y-m-d',$pre_sunday)." 00:00:00";
    $next_satday = date('Y-m-d',$next_satday)." 23:59:59";
    $date_array =   array();
    $date_array['sdoflw'] = $pre_sunday;
    $date_array['edoflw'] = $next_satday;
    return $date_array;
}
$date_array = getlastweek_first_last_date();
echo $start_date_of_week = $date_array['sdoflw'];
echo $end_date_of_week = $date_array['edoflw'];
</code>

您可以简单地获得如下日期

一周的第一天是星期一

date('Y-m-d',strtotime('Monday this week'));

如果第一天是星期天

date('Y-m-d',strtotime('Sunday this week'));