I am trying to write a function to determine if a string is a date/time using PHP. Basically a valid date/time would look like:
2012-06-14 01:46:28
Obviously though its completely dynamic any of the values can change, but it should always be in form of XXXX-XX-XX XX:XX:XX, how can I write a regular expression to check for this pattern and return true if matched.
If that's your whole string, then just try parsing it:
if (DateTime::createFromFormat('Y-m-d H:i:s', $myString) !== FALSE) {
// it's a date
}
I use this function as a parameter to the PHP filter_var function.
yyyy-mm-dd hh:mm:ss formatfunction filter_mydate($s) {
if (preg_match('@^(\d\d\d\d)-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)$@', $s, $m) == false) {
return false;
}
if (checkdate($m[2], $m[3], $m[1]) == false || $m[4] >= 24 || $m[5] >= 60 || $m[6] >= 60) {
return false;
}
return $s;
}
I wouldn't use a Regex for this, but rather just split the string and check that the date is valid:
list($year, $month, $day, $hour, $minute, $second) = preg_split('%( |-|:)%', $mydatestring);
if(!checkdate($month, $day, $year)) {
/* print error */
}
/* check $hour, $minute and $second etc */
Here's a different approach without using a regex:
function check_your_datetime($x) {
return (date('Y-m-d H:i:s', strtotime($x)) == $x);
}
strtotime? Lists? Regular expressions?
What's wrong with PHP's native DateTime object?
If your heart is set on using regEx then txt2re.com is always a good resource:
<?php
$txt='2012-06-14 01:46:28';
$re1='((?:2|1)\\d{3}(?:-|\\/)(?:(?:0[1-9])|(?:1[0-2]))(?:-|\\/)(?:(?:0[1-9])|(?:[1-2][0-9])|(?:3[0-1]))(?:T|\\s)(?:(?:[0-1][0-9])|(?:2[0-3])):(?:[0-5][0-9]):(?:[0-5][0-9]))'; # Time Stamp 1
if ($c=preg_match_all ("/".$re1."/is", $txt, $matches))
{
$timestamp1=$matches[1][0];
print "($timestamp1)
";
}
?>
Although this has an accepted answer, it is not going to effectively work in all cases. For example, I test date validation on a form field I have using the date "10/38/2013", and I got a valid DateObject returned, but the date was what PHP call "overflowed", so that "10/38/2013" becomes "11/07/2013". Makes sense, but should we just accept the reformed date, or force users to input the correct date? For those of us who are form validation nazis, We can use this dirty fix: https://stackoverflow.com/a/10120725/486863 and just return false when the object throws this warning.
The other workaround would be to match the string date to the formatted one, and compare the two for equal value. This seems just as messy. Oh well. Such is the nature of PHP dev.
function validateDate($date, $format = 'Y-m-d H:i:s')
{
$d = DateTime::createFromFormat($format, $date);
return $d && $d->format($format) == $date;
}
If you have PHP 5.2 Joey's answer won't work. You need to extend PHP's DateTime class:
class ExDateTime extends DateTime{
public static function createFromFormat($frmt,$time,$timezone=null){
$v = explode('.', phpversion());
if(!$timezone) $timezone = new DateTimeZone(date_default_timezone_get());
if(((int)$v[0]>=5&&(int)$v[1]>=2&&(int)$v[2]>17)){
return parent::createFromFormat($frmt,$time,$timezone);
}
return new DateTime(date($frmt, strtotime($time)), $timezone);
}
}
and than you can use this class without problems:
ExDateTime::createFromFormat('d.m.Y G:i',$timevar);
In case you don't know the date format:
/**
* Check if the value is a valid date
*
* @param mixed $value
*
* @return boolean
*/
function isDate($value)
{
if (!$value) {
return false;
}
try {
new \DateTime($value);
return true;
} catch (\Exception $e) {
return false;
}
}
var_dump(isDate('2017-01-06')); // true
var_dump(isDate('2017-13-06')); // false
var_dump(isDate('2017-02-06T04:20:33')); // true
var_dump(isDate('2017/02/06')); // true
var_dump(isDate('3.6. 2017')); // true
var_dump(isDate(null)); // false
var_dump(isDate(true)); // false
var_dump(isDate(false)); // false
var_dump(isDate('')); // false
var_dump(isDate(45)); // false
A smaller version, it might help:
if(strtotime($date_string)){
// it's in date format
}
In my project this seems to work:
function isDate($value) {
if (!$value) {
return false;
} else {
$date = date_parse($value);
if($date['error_count'] == 0 && $date['warning_count'] == 0){
return checkdate($date['month'], $date['day'], $date['year']);
} else {
return false;
}
}
}
if (strtotime($date)>strtotime(0)) { echo 'it is a date' }