Php 如何检查时间戳是否在DST夏令时？

问题是，例如，在某些时区，秋季的2:00am或2:59am是双倍的，而在DST省时更改期间，春季不存在这种情况

如果我在一整年中每分钟都运行一个PHP循环，我如何在循环中捕捉DST的省时时间？（在当前时区中，由设置）

如何完成与PHP 5.2兼容的函数，如：

<?php
/** returns true if a time is skipped or doubled 
 * (for example "2013-03-10 02:30" doesen't exist in USA)
 * 
 * @param string $season
 * @param string $datestring in the form of "2013-03-10 02:30"
 * @return boolean
 **/
function checkDST($datestring,$season="any"){
    $tz=date_default_timezone_get();
    $season=strtolower(trim($season));
    if($season=="spring"){
        if(/* an hour skipped */) return true;  
    }else if($season=="autumn"){
        if(/* double hour */) return true;  
    } else if($season=="any") {
        if(/* any of both */) return true;
    }
    return false
}

及

（时区见：）

---

编辑：
我发现了如何检测弹簧DST：

function checkDST($datestring,$season="any"){
    var_dump('checking '.$datestring);
    $season=strtolower(trim($season));
    $datestring=substr($datestring,0,16);
    if($season!="autumn" and date("Y-m-d H:i",strtotime($datestring))!=$datestring) {
        return true;
    }
    // check for double hours in autumn
    ...

---

如果您使用PHP的date\u default\u timezone\u集来解析我假设的Unix时间戳，那么时间戳将相对于该时区进行解析。若要确定夏令时偏移（如果相关），请执行以下操作

与示例中类似的函数可能如下所示：

<?php
function checkDST($datestring, $season, $tz = "America/New_York", $minutes_from_now_to_check = 1){
    $seconds_to_check = ($minutes_from_now_to_check * 60) + 30;
    if (!$tz) $tz = date_default_timezone_get();
    $timestamp = strtotime($datestring);
    $timestamp_start = new DateTime();
    $timestamp_start->setTimestamp($timestamp);
    $timestamp_end = new DateTime();
    $timestamp_end->setTimestamp($timestamp)->add(new DateInterval('PT'.$seconds_to_check.'S'));

    $timezone = new DateTimeZone($tz);
    $transitions = $timezone->getTransitions($timestamp_start->getTimestamp(), $timestamp_end->getTimestamp());
    if (count($transitions) > 1) { // there's an imminent DST transition, spring or fall
        if (strtolower($season) == "spring" && $transitions[1]["isdst"] === true){
            return true;    
        } 
        if (strtolower($season)=="autumn" && $transitions[1]["isdst"] === false){
            return true;
        }
        if (strtolower($season)=="any"){
            return true;
        }
    }
    return false;
}

$is_skipped = checkDST("2013-03-10 01:59","spring");
var_dump($is_skipped); // will display bool(true)

$is_skipped = checkDST("2013-03-10 12:30","spring");
var_dump($is_skipped); // will display bool(false)

$exists_two_times=checkDST("2013-11-03 01:59","autumn");
var_dump($exists_two_times); // bool(true)

$exists_two_times=checkDST("2013-11-03 03:00","autumn");
var_dump($exists_two_times); // bool(false)

---

这在任何时候都有效

date_default_timezone_set("America/New_York");

只有一个bug，如果我把它称为欧洲，它说现在比现在早了一个小时：

date_default_timezone_set("Europe/Berlin");
var_dump(checkDST("2013-10-27 01:30","any"));
var_dump(checkDST("2013-10-27 02:30","any"));

（欧洲的储蓄时间是从凌晨2点到凌晨3点）

这是到目前为止的结论：

<?php
/** returns true if a time is skipped or doubled 
 * (for example "2013-03-10 02:30" doesen't exist in USA)
 * 
 * @param string $season "spring", "autumn", "fall" or any other string for any of the time changes
 * @param string $datestring in the form of "2013-03-10 02:30"
 * @return boolean
 **/
function checkDST($datestring, $season, $tz = null){
    $debug=true;
    if($debug) echo ('checking '.$season.' '.$datestring);
    $season=strtolower(trim($season));
    if($season=="fall") $season="autumn";
    $datestring=substr($datestring,0,16);
    $monthdaystring=substr($datestring,0,10);
    if(!strtotime($datestring) or date("Y-m-d",strtotime($monthdaystring))!=$monthdaystring) {
        //Error
        if($debug) echo "<br>Error: not a correct datestring: $datestring";
        return false;
    }
    if($season!="autumn" and date("Y-m-d H:i",strtotime($datestring))!=$datestring) {
        // spring or any
        if($debug) echo "<br>".(date("Y-m-d H:i",strtotime($datestring)).'!='.$datestring);
        return true;
    } else if($season=="spring") {
        // spring ends here
        return false;
    }
    // "autumn" or "any" 
    $timestamp = strtotime($datestring);

    $timestamp_start = new DateTime();
    $timestamp_start->setTimestamp($timestamp);
    $timestamp_end = new DateTime();
    $timestamp_end->setTimestamp($timestamp)->add(new DateInterval('PT3600S'));

    if (!$tz) $tz = date_default_timezone_get();
    $timezone = new DateTimeZone($tz);
    $transitions = $timezone->getTransitions($timestamp_start->getTimestamp(), $timestamp_end->getTimestamp());
    if (count($transitions) > 1) { // there's an imminent DST transition, spring or fall
        // autumn
        if($debug) echo "<br>NumTransitions: ".(count($transitions));
        if($debug) var_dump($transitions);
        return true;
    }
    return false;
}

为什么时间翻倍首先是个问题？因为我想在特定的时间给药，而且患者不应该在当晚服用双倍剂量的药片，并在药片上加上一张便条：）这很有意义：）你能编辑这两个例子以包含你想要检查的特定日期字符串值吗？我刚刚编辑了我的答案，以获取一个日期字符串，并可以选择使用
日期\默认\时区\集
。我还将检查的时间间隔更改为31分钟（而不是之前的一小时），以便它与您描述的30分钟时间间隔数组更精确地关联。以何种方式
strotime
返回2:30？当我使用php内置的EST时区将其输入到一个
DateTime
类中时，我得到：
“2013-03-10 01:30:00”
…据我所知，夏令时转换发生在凌晨1:59=>3:00（至少在春季），有一些错误：
检查DST（“2013-03-10 01:58”，“春季”）返回错误我认为你的方法不起作用。更好的方法是从输入日期字符串创建一个时间戳，并将其转换回日期字符串“Y-m-dh:i”，然后比较是否发生了更改。因为初始的
strotime
已经显示，输入时间不存在。它以什么方式不工作？你运行代码并看到结果了吗？我的方法检查当前分钟，看看夏令时是否在下一分钟发生。这满足了您原来的问题，但您已经多次更改了问题。如果它不起作用，而你有更好或不同的方法，你应该发布它。
date_default_timezone_set("Europe/Berlin");
var_dump(checkDST("2013-10-27 01:30","any"));
var_dump(checkDST("2013-10-27 02:30","any"));

<?php
/** returns true if a time is skipped or doubled 
 * (for example "2013-03-10 02:30" doesen't exist in USA)
 * 
 * @param string $season "spring", "autumn", "fall" or any other string for any of the time changes
 * @param string $datestring in the form of "2013-03-10 02:30"
 * @return boolean
 **/
function checkDST($datestring, $season, $tz = null){
    $debug=true;
    if($debug) echo ('checking '.$season.' '.$datestring);
    $season=strtolower(trim($season));
    if($season=="fall") $season="autumn";
    $datestring=substr($datestring,0,16);
    $monthdaystring=substr($datestring,0,10);
    if(!strtotime($datestring) or date("Y-m-d",strtotime($monthdaystring))!=$monthdaystring) {
        //Error
        if($debug) echo "<br>Error: not a correct datestring: $datestring";
        return false;
    }
    if($season!="autumn" and date("Y-m-d H:i",strtotime($datestring))!=$datestring) {
        // spring or any
        if($debug) echo "<br>".(date("Y-m-d H:i",strtotime($datestring)).'!='.$datestring);
        return true;
    } else if($season=="spring") {
        // spring ends here
        return false;
    }
    // "autumn" or "any" 
    $timestamp = strtotime($datestring);

    $timestamp_start = new DateTime();
    $timestamp_start->setTimestamp($timestamp);
    $timestamp_end = new DateTime();
    $timestamp_end->setTimestamp($timestamp)->add(new DateInterval('PT3600S'));

    if (!$tz) $tz = date_default_timezone_get();
    $timezone = new DateTimeZone($tz);
    $transitions = $timezone->getTransitions($timestamp_start->getTimestamp(), $timestamp_end->getTimestamp());
    if (count($transitions) > 1) { // there's an imminent DST transition, spring or fall
        // autumn
        if($debug) echo "<br>NumTransitions: ".(count($transitions));
        if($debug) var_dump($transitions);
        return true;
    }
    return false;
}