Solved

php subtract days from string date

Posted on 2009-04-01
7
2,072 Views
Last Modified: 2013-12-12
i have a string, in european date format like this: 24/11/2009
i would like to subtract 28 days from the date and as output get a string variable with value 27/10/2009 (output in this format exactly)

i tried smth like the code below, but it does not work, could you please help me get the code right?
date_default_timezone_set('Europe/London');
$mudate = new DateTime("24/11/2009");
date_sub($mudate, new DateInterval("P28D"));

Open in new window

0
Comment
Question by:KristjanLaane
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
  • 2
7 Comments
 
LVL 9

Expert Comment

by:Rurne
ID: 24041068
Several things.

1.  Line 2 can fail, depending on your host.  DateTime expects a string as strtotime() can parse; according to the documentation, that's US English-style, so your switching of days and months might cause some problems.
2.  DateTime::sub doesn't actually modify the original DateTime object, but instead returns a new copy:
<?php
$mudate = new DateTime('2009-11-24', 'Europe/London');
$muinterval = new DateInterval('P28D');
$mudate->sub($muinterval);
echo $mudate->format('d/m/Y')."\n";    // prints '24/11/2009';
$newmudate = $mudate->sub($muinterval);
echo $newmudate->format('d/m/Y')."\n"; // prints '27/11/2009';
?>

Open in new window

0
 
LVL 5

Assisted Solution

by:pghn
pghn earned 100 total points
ID: 24041179
Try something like this:

(Since strtotime() I've found to be very good and reliable on parsing any date formate and coming up with the proper timestamp.)
$mudate = new DateTime("24/11/2009");
$newtimestamp = strtotime("-28 days",strtotime($mudate));
$newtimestamp = date("Y-m-d");

Open in new window

0
 
LVL 5

Expert Comment

by:pghn
ID: 24041192
Just a correction since you want in the format d/m/Y;

Line 3 it should be:
$newtimestamp = date("d/m/Y");

Open in new window

0
MS Dynamics Made Instantly Simpler

Make Your Microsoft Dynamics Investment Count  & Drastically Decrease Training Time by Providing Intuitive Step-By-Step WalkThru Tutorials.

 

Author Comment

by:KristjanLaane
ID: 24061483
the second line of Rurne code and the first line of pghn code causes an error, so the subsequent lines are of no use at the moment. i do not seem to be able to declare a date, do you have ideas how i could get around that?

and not even the following works:


$mudate = date_create('2008-08-03 14:52:10');

Open in new window

0
 

Author Comment

by:KristjanLaane
ID: 24061513
might it be because my server is PHP Version 5.0.3 ? I cannot update the version at the moment as im not admin ...
0
 
LVL 9

Accepted Solution

by:
Rurne earned 400 total points
ID: 24061947
Yes.  DateInterval is not available for versions before 5.3.0.  Your alternative is to work something around strtotime(), get the timestamp, and manipulate it directly.  The below code is a fairly verbose example:
// setting up constants for explanation purposes only
define("SECONDS_PER_MINUTE", 60);
define("MINUTES_PER_HOUR", 60);
define("HOURS_PER_DAY", 24);
 
$day_interval = 28;  // aka DateInterval('P28D');
 
$beginning_timestamp = strtotime('2009-11-24');
$interval = $day_interval * SECONDS_PER_MINUTE * MINUTES_PER_HOUR * HOURS_PER_DAY;
$new_timestamp = $beginning_timestamp - $interval;
echo date('m/d/Y', $new_timestamp)."\n";  // prints "10/27/2009"

Open in new window

0
 

Author Comment

by:KristjanLaane
ID: 24064669
thanks, this works great ! strtotime seems to have read the date in in US format, so i changed my initial requirement of european data input and converted it to US date format first.
0

Featured Post

On Demand Webinar: Networking for the Cloud Era

Ready to improve network connectivity? Watch this webinar to learn how SD-WANs and a one-click instant connect tool can boost provisions, deployment, and management of your cloud connection.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction This article is intended for those who are new to PHP error handling (https://www.experts-exchange.com/articles/11769/And-by-the-way-I-am-New-to-PHP.html).  It addresses one of the most common problems that plague beginning PHP develop…
This post looks at MongoDB and MySQL, and covers high-level MongoDB strengths, weaknesses, features, and uses from the perspective of an SQL user.
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…
The viewer will learn how to create and use a small PHP class to apply a watermark to an image. This video shows the viewer the setup for the PHP watermark as well as important coding language. Continue to Part 2 to learn the core code used in creat…

707 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question