我正在寻找一种方法来显示当前星期的日期或过去的日期，也许使用周数？
我试过了
echo date('d/m/Y', strtotime('previous monday'));
但显然这不适用于当前日期或未来日期
任何人都可以帮忙 - 我是新手！ 谢谢
【问题讨论】：
如果你想要一周的日期，你可以使用这个代码
$week_start = new DateTime();
$week_start->setISODate($year,$week_no);
echo $week_start->format('d-M-Y');
我没有测试过它，但我认为它会给你一个星期一的日期，你可以从这个日期出发，而不是去其他日子。
来源：http://www.lornajane.net/posts/2011/getting-dates-from-week-numbers-in-php
【讨论】：
这就是我要做的。基本上找到最后一个星期天（除非目标日期是星期天），然后循环过去直到星期六。
<?php
//our target timestamp to get the week
// $targetDate = time(); //today
$targetDate = strtotime('1-Jan-2015'); //specific date
//if target day is not day 0 (sunday)
if(date('w', $targetDate) > 0) {
//get the last sunday
$sunday = strtotime('last sunday', $targetDate);
} else {
//target day is sunday, get target date
$sunday = $targetDate;
}
//if you want shorthand ternary statement, this would work for finding sunday. I wrote it out above so it is easier to understand:
// $sunday = date('w', $targetDate) ? strtotime('last sunday', $targetDate) : $targetDate;
//get the following saturday as our stop point
$saturday = strtotime('saturday', $sunday);
//loop over each day of the week
for(
$currentDay = $sunday; //start on sunday
$currentDay <= $saturday; //while we aren't on saturday yet
$currentDay = strtotime('+1 day', $currentDay) //add one day after each loop
){
//echo out current day's date
echo date('d-M-Y', $currentDay).'<br>';
}
我个人更喜欢这个，因为您还可以在循环中执行其他操作，例如回显特定日期的某些值。
【讨论】：
下面的sn-p应该根据你输入的星期给你前几天：
$weeks = 1;
$weekdays = ['monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'saturday', 'sunday'];
$first_day_current_year = mktime(0, 0, 0, 1, 1, date('Y', time())); // d/m/Y H:i:s => 01/01/YYYY 00:00:00
$n_weeks_after = strtotime('+ '. $weeks . ' week', $first_day_current_year); // d/m/Y H:i:s => 08/01/YYYY 00:00:00
$result = ['reference date' => date('l, d/m/Y, H:i:s', $n_weeks_after)];
foreach ($weekdays as $day) {
$weekday = strtotime('previous ' . $day, $n_weeks_after);
$result['previous ' . $day] = date('l, d/m/Y, H:i:s', $weekday);
}
echo '<pre>';
print_r($result);
echo '</pre>';
在这个例子中，我设置了$weeks = 1，所以它的范围是从 1 月 1 日（星期四）到 1 月 7 日（星期三）。
下面的输出：
Array
(
[reference date] => Thursday, 08/01/2015, 00:00:00
[previous monday] => Monday, 05/01/2015, 00:00:00
[previous tuesday] => Tuesday, 06/01/2015, 00:00:00
[previous wednesday] => Wednesday, 07/01/2015, 00:00:00
[previous thursday] => Thursday, 01/01/2015, 00:00:00
[previous friday] => Friday, 02/01/2015, 00:00:00
[previous saturday] => Saturday, 03/01/2015, 00:00:00
[previous sunday] => Sunday, 04/01/2015, 00:00:00
)
对于当前一周，您可以将$weeks 设置为：
$weeks = date('W', time()); // ISO-8601 week number of year, weeks starting on Monday (added in PHP 4.1.0)
你可以在这里测试它：http://www.writephponline.com/
【讨论】：
这是一个使用周数获取日期的函数。
第一个参数是周数（1=一年中的第一周，模式设置为 ISO），
第二个参数是工作日索引（0-6，0=星期一，6=星期日）
前三个参数是可选的，否则设置为当前值。
如果没有任何参数，您将以您在问题中使用的格式获得当前日期。
如果您将第二个参数（工作日）设置为 7（或更高），您将获得一周中所有日期的数组。
使用“H:i”格式，您可以看到夏令时的偏移量，例如夏季为“01:00”，否则为“00:00”。
function getWeekDate($week=-1, $weekday=-1, $year=-1, $format="d/m/Y", $mode="ISO") {
// default is the current
if($week < 0) { $week = date("W"); }
if($weekday < 0) { $weekday = date("w")-1; }
if($weekday < 0) { $weekday+= 7; } // on sundays
if($year < 0) { $year = date("Y"); }
$time = strtotime("1 January $year", time());
$day = date('w', $time);
if($mode=="ISO") {
// ISO 8601: first week of the year is the week with the first thursday
if($day<=4) { $day+= 7; }
}
$time+= ((7*$week)+1-$day)*24*3600;
$return = array();
for($i=0;$i<=6;$i++) {
$return[$i] = date($format, $time);
$time+= 24*3600;
}
if(isset($return[$weekday])) {
$return = $return[$weekday];
}
return $return;
}
// Examples:
echo "<br>Current Date: ".getWeekDate();
echo "<br>Monday of the Current Week: ".getWeekDate(-1,0);
echo "<br>Sunday of the Next Week: ".getWeekDate(date("W")+1,6);
echo "<br>All Days of Week 28: ".print_r(getWeekDate(28,7),true);
【讨论】：