在给定的周数的“Y-m-d”中获取周的第一天(重复)

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im trying to get the first day of a given week based on inputting a week number and year. im currently using this for the current week and year and works like a charm.

我试着输入一个星期的数字和年份来得到一个星期的第一天。我现在在这周和这一年都在使用它，它就像一种魅力。

$week = date('W');
$year = date('Y');
$date1 = date('Y-m-d', strtotime($year."W".$week.'1'));

however when i try to input my own week and year it doesn't work

然而，当我尝试输入我自己的一周和一年的数据时，它就不管用了

$week = 7;
$year = 2013;
$date1 = date('Y-m-d', strtotime($year."W".$week.'1'));

what type if string should i be using for strtotime? how come providing my own date doesn't work?

strtotime应该使用什么类型的字符串?为什么提供我自己的约会不成功?

1 个解决方案

#1

Because the week numbers are supposed to be padded (and the extra 1 at the end doesn't really do anything):

因为这周的数字应该是padd(而最后的额外的1并没有什么作用):

$date1 = date(
    'Y-m-d', 
    strtotime($year . 'W' . str_pad($week, 2, '0', STR_PAD_LEFT))
);