DateTime::createFromFormat in PHP < 5.3.0

Question

I'm looking for a function identical to DateTime::createFromFormat but I need it to work in an environment running a version of PHP which is older than v5.3. Basically I need to provide a format, like you'd use with the Date() function, and I then need to parse/validate a string against that format, and return a timestamp if the string is formatted correctly and a valid date.

Anyone know where I can find something like that, or do I have to write it myself?

Again, this has to work with a specific format, provided as an argument. The format could be anything, so there's no guarantee I can just use strtotime().

Answer 1

DateTime::createFromFormat and date_parse_from_format have been added in PHP 5.3 because there was a high demand for that feature, especially from developpers who code for users who don't use US date/time formats.

Before those, you had to develop a specific function to parse the format you were using ; with PHP < 5.3, what is generally done is :

• Decide which format will be accepted by the application
• Display some message saying something like "your input should be JJ/MM/AAAA" (French for DD/MM/YYYY)
• Check that the input is OK, regarding to that format
• And parse it to convert it to a date/time that PHP can understand.

Which means applications and developpers generally didn't allow for that many formats, as each format meant one different additionnal validation+parsing function.

If you really need that kind of function, that allows for any possible format, I'm afraid you'll kind of have to write it yourself :-(

Maybe taking a look at the sources of date_parse_from_format could help, if you understand C code ? It should be in something like ext/date/php_date.c -- but doesn't seem to be that simple : it's calling the timelib_parse_from_format function, which is defined in ext/data/lib/parse_date.c, and doesn't look that friendly ^^

Answer 2

You can use Zend_Date class from Zend Framework: http://framework.zend.com/manual/en/zend.date.html

$date = new Zend_Date($string, $format);
$timestamp = $date->get();

Answer 3

You may use strptime() - it's using strftime() format. A bit different compared to date() format but does almost the same things.

function createFromFormat($strptimeFormat, $date) {
    $date = strptime($date, $strptimeFormat);
    $date['tm_year'] += 1900;
    $date['tm_mon']++;
    $timestamp = mktime($date['tm_hour'], $date['tm_min'], $date['tm_sec'], $date['tm_mon'], $date['tm_mday'], $date['tm_year']);
    return new DateTime('@'. $timestamp);
}

Answer 4

For PHP version prior to 5.3 I use this function bellow to get DateTime object form strings formated as 'DD.MM.YYYY'.

function ParseForDateTimeValue ($strText)
{
    if ($strText != "")
    {
        if (ereg("^([0-9]{1,2})[/\.]\s*([0-9]{1,2})[/\.]\s*([0-9]{2,4})$",$strText,$arr_parts)) {

            $month = ltrim($arr_parts[2], '0');
            $day = ltrim($arr_parts[1], '0');
            $year = $arr_parts[3];

            if (checkdate($month, $day, $year)) {
               return new DateTime(date('Y-m-d H:i:s', mktime(0, 0, 0, $month, $day, $year));
            }
        }
    }
    return NULL;
}

• First validate if input is correct.
• Then extract month, day and year
• Use checkdate to validate the date.
• Convert it to timestamp and pass it to contructor of DateTime and return it.

Answer 5

You can create a timestamp and then run it through date.. to create the timestamp you can do some explode on the string you get..

$tomorrow = mktime(0,0,0,date("m"),date("d")+1,date("Y"));
echo "Tomorrow is ".date("Y/m/d", $tomorrow);