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', $myString) !== false) { // it's a date } 
DateTime::createFromFormat('m/d/Y', '10/38/2013') and that produces a valid DateTime object and not false. The date is converted to object(DateTime)#39 (3) { ["date"]=> string(19) "2013-11-07 23:45:55" ["timezone_type"]=> int(3) ["timezone"]=> string(3) "UTC" }
Tue Oct 30 05:51:41 GMT+05:30 2018 how can we check it?, is there any common way of doing?Easiest way to check if a string is a date:
if(strtotime($date_string)){ // it's in date format } 
strtotime('a string'); -> returns current time.
+
strtotime("2021-02-31 08:00:00") will return int(1614787200) which evaluates to TRUE but it isn't a valid datetime string as OP asked forHere's a different approach without using a regex:
function check_your_datetime($x) { return (date('Y-m-d H:i:s', strtotime($x)) == $x); } 
"2023-02-29" is false and "2020-02-29" is true. FYI, depending on your use case, you can optionally remove the "H:i:s" if you only care about date (and not time of day)
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 $e) { return false; } } var_dump(isDate('2017-01-06')); // true var_dump(isDate('2017-13-06')); // false var_dump(isDate('2017-02-06T04:20:33')); // true var_dump(isDate('2017/02/06')); // true var_dump(isDate('3.6. 2017')); // true var_dump(isDate(null)); // false var_dump(isDate(true)); // false var_dump(isDate(false)); // false var_dump(isDate('')); // false var_dump(isDate(45)); // false 
In my project this seems to work:
function isDate($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'], $date['year']); } else { return false; } } } 
date_parse function from showing false positive errors. The function presumes that slash-separated date string is in North American format and a dash-separated date string is a European-style date. Therefore, a string like 30/9/2022 will show errors, but a 30-9-2022 string will pass with no problems. Interesting.
I use this function as a parameter to the PHP filter_var function.
yyyy-mm-dd hh:mm:ss formatfunction filter_mydate($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 $s; } 
if (strtotime($date) > strtotime(0)) { echo 'it is a date' } 
A simple solution is:
echo is_numeric( strtotime( $string ) ) ? 'Yes' : 'No'; 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.
I found my answer here https://stackoverflow.com/a/19271434/1363220, bassically
$d = DateTime::createFromFormat($format, $date); // The Y ( 4 digits year ) returns TRUE for any integer with any number of digits so changing the comparison from == to === fixes the issue. if($d && $d->format($format) === $date) { //it's a proper date! } else { //it's not a proper date } I wouldn't use a Regex for this, but rather just split the string and check that the date is valid:
list($year, $month, $day, $hour, $minute, $second) = preg_split('%( |-|:)%', $mydatestring); if(!checkdate($month, $day, $year)) { /* print error */ } /* check $hour, $minute and $second etc */ 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 "($timestamp1) \n"; } ?> If you have PHP 5.2 Joey's answer won't work. You need to extend PHP's DateTime class:
class ExDateTime extends DateTime{ public static function createFromFormat($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); 
function validateDate($date, $format = 'Y-m-d H:i:s') { $d = DateTime::createFromFormat($format, $date); return $d && $d->format($format) == $date; } This solves for me, but also presents various other problems I think.
function validateTimeString($datetime, $format = "Y-m-d H:i:s"){ return ($datetime == date($format, strtotime($datetime))); } When I work with unconventional APIs, I sometimes get a bit of a messy return instead of a well defined date format. So I use a rather inelegant class and I readily admit that it is brutal and unconventional in principle but it does me good sometimes ^^.
class DateHelper { private const DATE_FORMATS = [ DATE_ATOM, DATE_COOKIE, DATE_RFC822, DATE_RFC850, DATE_RSS, DATE_W3C, "Y-m-d\TH:i:s.u", 'Y-m-d\TH:i:s', "Y-m-d'T'H:i:s.SSS'Z'", "Y-m-d\TH:i:s.uP", "Y-m-d\TH:i:sP", "d/m/Y H:i:s", ]; /** * @param string $inputStringDate * @return DateTime|null */ public static function createDateFromUnknownFormat(string $inputStringDate): ?DateTime { $inputStringDate = str_replace('/', '-', $inputStringDate); preg_match('/^(\d{4})\-(\d{2})-(\d{2})$/', $inputStringDate, $result); if (!empty($result)) { return DateTime::createFromFormat('Y-m-d', $inputStringDate); } preg_match('/^(\d{2})\-(\d{2})-(\d{4})$/', $inputStringDate, $result); if (!empty($result)) { return DateTime::createFromFormat('d-m-Y', $inputStringDate); } foreach (self::DATE_FORMATS as $dateFormat) { if ($dateObject = DateTime::createFromFormat($dateFormat, $inputStringDate)) { return $dateObject; } } return null; } } strtotime? Lists? Regular expressions?
What's wrong with PHP's native DateTime object?
