如何让时间下拉框默认为当前时间？

发布于 2024-12-15 11:16:11 字数 554 浏览 2 评论 0原文

我有一个 PHP 脚本，用于选择下拉框以 15 分钟为间隔显示时间；但是，我希望将其默认为最接近的当前时间（根据 15 分钟间隔向上或向下舍入）。有什么想法吗？

date_default_timezone_set($_SESSION['TIME_ZONE'])

<label id="time_label" for="time" class="label">Time:</label>

<select id="time" name="time">

    <option value="">Select</option>

    <?

       $start = strtotime('12:00am');
       $end = strtotime('11:59pm');
       for ($i = $start; $i <= $end; $i += 900){
           echo '<option>' . date('g:i a', $i);
       }
    ?>

</select>

原文

I have a PHP script for a select dropdown box to display times in 15 minute intervals; however, I'd like to have it default to the closest current time (rounding up or down based on 15 minute interval). Any ideas?

date_default_timezone_set($_SESSION['TIME_ZONE'])

<label id="time_label" for="time" class="label">Time:</label>

<select id="time" name="time">

    <option value="">Select</option>

    <?

       $start = strtotime('12:00am');
       $end = strtotime('11:59pm');
       for ($i = $start; $i <= $end; $i += 900){
           echo '<option>' . date('g:i a', $i);
       }
    ?>

</select>

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柠北森屋 2024-12-22 11:16:12

这里有一个方便的方法来获取当前时间向上或向下舍入：

$time = time();
$rounded_time = $time % 900 > 450 ? $time += (900 - $time % 900):  $time -= $time % 900;

$start = strtotime('12:00am');
$end = strtotime('11:59pm');
for( $i = $start; $i <= $end; $i += 900) 
{
    $selected = ( $rounded_time == $i) ? ' selected="selected"' : '';
    echo '<option' . $selected . '>' . date('g:i a', $i) . '</option>';
}

您可以使用下面的演示来测试，只需将 450 或 900 添加到 $time 变量即可。

编辑：根据下面的评论，有一个条件会失败，因为四舍五入的时间会导致滚动到第二天。要修复此问题，请将 $selected 行修改为：

$selected = ( ($rounded_time - $i) % (86400) == 0) ? ' selected="selected"' : '';

这会忽略日期部分，仅检查时间。我更新了下面的演示以反映这一变化。

演示

Here is a convenient way to get the current time rounded up or down:

$time = time();
$rounded_time = $time % 900 > 450 ? $time += (900 - $time % 900):  $time -= $time % 900;

$start = strtotime('12:00am');
$end = strtotime('11:59pm');
for( $i = $start; $i <= $end; $i += 900) 
{
    $selected = ( $rounded_time == $i) ? ' selected="selected"' : '';
    echo '<option' . $selected . '>' . date('g:i a', $i) . '</option>';
}

You can use the following demo to test, just add either 450 or 900 to the $time variable.

Edit: As per the comments below, there is one condition that will fail because the rounded up time results in a rollover to the next day. To fix it, modify the $selected line to:

$selected = ( ($rounded_time - $i) % (86400) == 0) ? ' selected="selected"' : '';

This ignores the date portion and just checks the time. I've updated the demo below to reflect this change.

Demo

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花辞树 2024-12-22 11:16:11

<label id="time_label" for="time" class="label">Time:</label>

<select id="time" name="time">

<option value="">Select</option>

<?php

$start = strtotime('12:00am');
$end = strtotime('11:59pm');
$now = strtotime('now');
$nowPart = $now % 900;
 if ( $nowPart >= 450) {
    $nearestToNow =  $now - $nowPart + 900;
    if ($nearestToNow > $end) { // bounds check
        $nearestToNow = $start;
    }
} else {
    $nearestToNow = $now - $nowPart;
}
for ($i = $start; $i <= $end; $i += 900){
    $selected = '';
    if ($nearestToNow == $i) {
        $selected = ' selected="selected"';
    }
    echo "\t<option" . $selected . '>' . date('g:i a', $i) . "\n";
}
?>

</select>

这是我留下的一些调试代码：

<?php

echo '<p></p>DEBUG $now = '. date('Y-m-d g:ia', $now) . "<br />\n";
echo "DEBUG \$nowPart = $nowPart<br />\n";
echo 'DEBUG $nearestToNow = '. date('Y-m-d g:ia', $nearestToNow) . "<br />\n";
?>

<label id="time_label" for="time" class="label">Time:</label>

<select id="time" name="time">

<option value="">Select</option>

<?php

$start = strtotime('12:00am');
$end = strtotime('11:59pm');
$now = strtotime('now');
$nowPart = $now % 900;
 if ( $nowPart >= 450) {
    $nearestToNow =  $now - $nowPart + 900;
    if ($nearestToNow > $end) { // bounds check
        $nearestToNow = $start;
    }
} else {
    $nearestToNow = $now - $nowPart;
}
for ($i = $start; $i <= $end; $i += 900){
    $selected = '';
    if ($nearestToNow == $i) {
        $selected = ' selected="selected"';
    }
    echo "\t<option" . $selected . '>' . date('g:i a', $i) . "\n";
}
?>

</select>

Here some debug code I left in:

<?php

echo '<p></p>DEBUG $now = '. date('Y-m-d g:ia', $now) . "<br />\n";
echo "DEBUG \$nowPart = $nowPart<br />\n";
echo 'DEBUG $nearestToNow = '. date('Y-m-d g:ia', $nearestToNow) . "<br />\n";
?>

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