Function to check if a string is a date

Question

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

User · Answer

I use this function as a parameter to the PHP filter var function     It checks for dates in yyyy-mm-dd hh mm ss format It rejects dates that match the pattern but still invalid  e g  Apr 31      function 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   gt   24     m 5   gt   60     m 6   gt   60            return false            return  s

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If your heart is set on using regEx then txt2re com is always a good resource    lt  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          gt

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if  strtotime  date  strtotime 0      echo  it is a date

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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

User · Answer

Easiest way to check if a string is a date   if strtotime  date string           it s in date format

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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

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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  amp  amp   d- gt format  format       date          it s a proper date    else         it s not a proper date

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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

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strtotime  Lists  Regular expressions   What s wrong with PHP s native DateTime object   http   www php net manual en datetime construct php

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function validateDate  date   format    Y-m-d H i s                 d   DateTime  createFromFormat  format   date            return  d  amp  amp   d- gt format  format      date         function was copied from this answer or php net

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In my project this seems to work   function isDate  value        if    value            return false        else            date   date parse  value           if  date  error count      0  amp  amp   date  warning count      0               return checkdate  date  month     date  day     date  year               else               return false

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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  gt  5 amp  amp  int  v 1  gt  2 amp  amp  int  v 2  gt 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

User · Answer

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

User · Answer

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

[php] Function to check if a string is a date

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