php - uniformize date strings with different formats - php

Question

I have an array with many different formats of dates. All strings.
I want to uniformize this into an array with dates(). Something like this:
function uniformize($str){
$date = strtotime($str);
return $date;
}
$arr = array(
'07/29/1975',
'20/01/1981',
'1983-05-24',
'10 /8 /1995'
);
print_r( array_map('uniformize', $arr) );
But this only works with one format:
Array (
[0] =>
[1] =>
[2] => 454215600
[3] =>
)
Is there any way I can do it for all formats?

Answer 1

You can use this function for that. Fiddle here
Notice it's supposed to have always the days before than the months. Otherwise it's impossible to know whether first part of the date is a day or a month (unless the day is more than 12.. and can't cover all the cases).
function date2time($date)
{
$date = str_replace(' ','',$date);
if(strpos($date,'-')!==false)
$date_array = explode('-',$date);
if(strpos($date,'/')!==false)
$date_array = explode('/',$date);
//add more delimiters if needed
$day = $month = $year = '';
foreach($date_array as $date_elem)
{
if(strlen($date_elem) < 3)
{
if(empty($day))
$day = $date_elem;
else
$month = $date_elem;
}else
$year = $date_elem;
}
$time = mktime(0,0,0,$month,$day,$year);
return $time;
}
$arr = array(
'07/29/1975',
'20/01/1981',
'1983-05-24',
'10 /8 /1995'
);
print_r( array_map('date2time', $arr) );

Answer 2

Unfortunately, I think you have to detect yourself the format and then convert it into the format you wish...
The real problem is about months and days...
some use 31-12-2014, other countries use 12-31-2014...
so you HAVE to define which is the month and the day in a string like 05-06-2015...
EDIT :
You have many regex to do...
I'm using this for 2015-12-31 format :
if(preg_match("/^([0-9]{4})-([0-9]{2})-([0-9]{2})$/", $yourDate, $split)) && (checkdate($split[2],$split[3],$split[1]))) {
// do stuff where $split[1] is years, split[2] is month, and split[3] is day
}
Then you may adapt it to every formats you encounter changing order...
checkdate checks if it is a valide date (2015-52-38 is not a valid date)
You may also find some on google with "date pattern regex" for instance...

Answer 3

The first two strings use / as component separator. The function strtotime consider them to be formatted according to the American format: month/day/year. Because 24 and 20 are invalid month numbers they cannot be parsed correctly.
The last string ('10 /8 /1995') looks like a short date format but the spaces inside the components also render it invalid.
As it is explained in a note in the documentation of function strtotime():
Note:
Dates in the m/d/y or d-m-y formats are disambiguated by looking at the separator between the various components: if the separator is a slash (/), then the American m/d/y is assumed; whereas if the separator is a dash (-) or a dot (.), then the European d-m-y format is assumed.
What can you do
If you know the order of components in your dates you can use str_replace() to always use / for m/d/y (the American format) and - for d-m-y (the European format). Also, you should strip the spaces.
Another option is to write your own date parser to identify the date components then use mktime() or DateTime::setDate() to get the date. However, if the date have both the day and the month in 1..12, the format cannot be detected and it have to be assumed (from the separator).