从php输入html中设置datetime值

I just try to set a value datetime for input( It is for change the current value of variable date time), but my html show an error ( seems it's fault about the format):

the code is :

<input type="datetime" name="deadline" required value ='<?php echo date('c', $dateDeadline); ?>'/>

Thx a lot.

If $dateDeadiline is indeed defined, your should wrap it with strtotime().

On the manual:

string date ( string $format [, int $timestamp = time() ] )

You should provide a timestamp, not a string date. Consider this example:

<?php
$dateDeadiline = '2014-06-21 12:32:00';
?>
<input type="datetime" name="deadline" required value="<?php echo date('c', strtotime($dateDeadiline)); ?>" />

Using DateTime Class with timezone:

<?php $date = new DateTime('2014-06-21 12:32:00', new DateTimeZone('America/New_York')); ?>
<input type="datetime" name="deadline" required value="<?php echo $date->format('c'); ?>" />

For list of supported timezones, you can check this link:

http://www.php.net//manual/en/timezones.php

You are using single quotes for your value attribute that are conflicting with your PHP code. Try this instead:

<input type="datetime" name="deadline" required value="<?php echo date('c', $dateDeadline); ?>" />