how to re-format datetime string in php?

I receive a datetime from a plugin. I put it into a variable:

$datetime = "20130409163705"; 

That actually translates to yyyymmddHHmmss.

I would need to display this to the user as a transaction time but it doesn't look proper.

I would like to arrange it to be like 09/04/2013 16:37:05 or 09-apr-2013 16:37:05.

How do I go about and change the orders of the string?

As for now I could think is to use substr to separate the date and time. I'm still not sure on how to add the additional characters and rearrange the date.

why not use date() just like below,try this

$t = strtotime('20130409163705');
echo date('d/m/y H:i:s',$t);

and will be output

09/04/13 16:37:05

For PHP 5 >= 5.3.0 http://www.php.net/manual/en/datetime.createfromformat.php

$datetime = "20130409163705"; 
$d = DateTime::createFromFormat("YmdHis", $datetime);
echo $d->format("d/m/Y H:i:s"); // or any you want

Result:

09/04/2013 16:37:05

date("Y-m-d H:i:s", strtotime("2019-05-13"))

If you want to use substr(), you can easily add the dashes or slashes like this..

$datetime = "20130409163705"; 
$yyyy = substr($datetime,0,4);
$mm = substr($datetime,4,6);
$dd = substr($datetime,6,8);
$hh = substr($datetime,8,10);
$MM = substr($datetime,10,12);
$ss = substr($datetime,12,14);
$dt_formatted = $mm."/".$dd."/".$yyyy." ".$hh.":".$MM.":".$ss;

You can figure out any further formatting from that point.

try this

$datetime = "20130409163705"; 
print_r(date_parse_from_format("Y-m-d H-i-s", $datetime));

the output:

[year] => 2013
[month] => 4
[day] => 9
[hour] => 16
[minute] => 37
[second] => 5

You could do it like this:

<?php
$datetime = "20130409163705"; 
$format = "YmdHis";

$date = date_parse_from_format ($format, $datetime);
print_r ($date);
?>

You can look at date_parse_from_format() and the accepted format values.

https://en.functions-online.com/date.html?command={"format":"l jS \\of F Y h:i:s A"}

You have different options.

Using date():

$format = date('d/m/y H:i:s', 1621371929);
echo $format;

the output is:

18/05/21 14:05:29

Using date_format():

$date = date_create(1621371929);
echo date_format($date, 'd/m/y H:i:s');

the output is:

18/05/21 14:05:29

Using DateTime::format():

$date = new DateTime('2021-05-18 14:05:29');
echo $date->format('d/m/y H:i:s');

the output is:

18/05/21 14:05:29

This article gives you an overview of these three methods, and this one is DateTime::format() in depth.

You can use date_parse_from_format() function ...

date_parse_from_format(string $format, string $datetime): array

Example

<?php
$date = "6.1.2009 13:00+01:00";
print_r(date_parse_from_format("j.n.Y H:iP", $date));
?>

The above example will output:

Array
(
    [year] => 2009
    [month] => 1
    [day] => 6
    [hour] => 13
    [minute] => 0
    [second] => 0
    [fraction] => 
    [warning_count] => 0
    [warnings] => Array
        (
        )

    [error_count] => 0
    [errors] => Array
        (
        )

    [is_localtime] => 1
    [zone_type] => 1
    [zone] => 3600
    [is_dst] => 
)

Check the PHP docs..you will get clear idea