regex to get date yyyy-mm-dd from any string

Question

first of all excuse me for not being regex familiar that much.What I Would like is a regex that will extract a date like mysql date from any type of string. Until now I was using this : ^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$

However now I want to extract date patterns from other strings and datetime strings I tried altering the regex to ^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1]). based on some online regex testers, but it fails. Also some times it gave me a result with a 3 digit day.

In other words sting starts with, yyyy-mm-dd and is followed up by spaces characters numbers or anything. How do I extract the date?

UPDATE

I'm testing regex with preg_match here: http://www.pagecolumn.com/tool/pregtest.htm

so far the only thing that seems to work is

[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])

http://stackoverflow.com/questions/5145133/preg-match-for-mysql-date-format — Dipesh Parmar, Oct 24 '13 at 11:05

revo · Answer 1 · 2013-10-24T11:15:43.420

8

If your string has more than one date form value occurrence and you wanna capture all of them you should use preg_match_all function and if it's not preg_match is enough. Also using ^ and $ means input string is should be just a date, so avoid it.

<?php
$input_string = "yes today is 2013-10-24";
if(preg_match("/\d{4}-\d{2}-\d{2}/", $input_string, $match))
{
    print_r($match);
}
else
    echo "not matched";
////////////////////////
/* Output:
Array
(
    [0] => 2013-10-24
)
*/

Live demo

edited Oct 24 '13 at 11:15

answered Oct 24 '13 at 11:04

revo

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no it will have only 1 date sorry for not being clear about this. – 0x_Anakin Oct 24 '13 at 11:06

Sunil Kumar · Answer 2 · 2013-10-24T11:11:11.853

6

Try this: you can use preg_match() or preg_match_all()

   $dateArray = preg_match("/(\d{4}-\d{2}-\d{2})/", $str, $match);

Then use strtotime and date

$date = date('Y-m-d',strtotime($match[0]));

edited Oct 24 '13 at 11:11

answered Oct 24 '13 at 11:05

Sunil Kumar

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score 4 · Accepted Answer · answered Oct 24 '13 at 11:03

To match dates wherever they appear, remove the $ and ^ anchors from your original regex.

To match dates at the start of any input remove the $ at the end (leave the ^).

You can also put the remaining pattern inside parentheses for convenience, so that the match is also captured as a whole.

Your suggested improvement has a spurious dot at the end which will match any character; that was the reason for returning matches with three-digit days.

score 2 · Answer 4 · answered Oct 24 '13 at 11:04

2

Just replace ^ for \b.

\b(\d{4}-\d{2}-\d{2})

answered Oct 24 '13 at 11:04

edi_allen

1,878
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score 1 · Answer 5 · answered Oct 24 '13 at 11:09

1

It is dot in the end of your regexp (it matches any character, except for line breaks) Try removing it

^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])

answered Oct 24 '13 at 11:09

Mizax

86
5

regex to get date yyyy-mm-dd from any string

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