Andrew Pollack's Blog

Technology, Family, Entertainment, Politics, and Random Noise

- CORRECTION - Having just wasted a good bit of the afternoon, here's a technote on setting cookie expiration dates for IE

By Andrew Pollack on 02/24/2008 at 12:41 PM EST

* Corrected on Feb 24.

Many of you super JavaScript programmers already know this, but since I didn't have it quite right I thought I'd post it here so that if someone else is searching for information they'll have an easier time of it.

When you set a cookie in JavaScript, you make it 'permanent' (make it last through browser restarts) by setting a parameter called "expires". There are web pages all over the place that will tell you about lots of different formats you can set that expiration date in. Many of them work for Mozilla and other other browsers.

For Internet Explorer -- particularly for Internet Explorer version 7 -- there is only one format that actually works in a reliable way. There are technotes that claim you can use "14 day" or "1 year" or "2 hours". There are technotes out there that claim you can use a unix numeric time value (the number of seconds since 1/1/1970). While these may work for other browsers, you will waste your time if you try them with IE7. Worse, it will not give you any error or indication that it failed. It simply won't keep the cookie if you restart the browser.

Yes, sometimes other formats work. Not reliably however. The "Correct" format* according to Microsoft is:

DAY, DD-MON-YYYY HH:MM:SS GMT

The values are as follows:

DAY = Mon, Tue, Wed, Thu, Fri, Sat, Sun
MON = A Three Letter Version of the Month (Jan, Feb, ...)
DD = A two digit number representing the Day
YYYY = A four digit number representing the Year
HH = A two digit number representing the hour, in 24 hour time format.
MM = A two digit number representing the Minute
SS = A two digit number representing the Second
GMT = Always set dates in GMT time, and include GMT on the string

For all numeric values, you MUST use both digits. Pad with a leading zero as needed

* I have noted that if you tell Microsoft's JavaScript implementation to output Date.toGMTString() you get this in the same format but without dashes between the date components:

DAY, DD-MON-YYYY HH:MM:SS GMT

Since the common JavaScript way to do this is to use a data object this way, it is safe to assume this is also supported. In my testing, it does work.


There are  - loading -  comments....



Other Recent Stories...

  1. 05/05/2016Is the growing social-sourced economy the modern back door into socialism?Is the growing social-sourced economy the modern back door into socialism? I read a really insightful post a couple of days ago that suggested the use of social network funding sites like “Go Fund Me” and “Kickstarter” have come about and gained popularity in part because the existing economy in no longer serving its purpose for anyone who isn’t already wealthy. Have the traditional ways to get new ventures funded become closed to all but a few who aren’t already connected to them and so onerous as to make ...... 
  2. 04/20/2016Want to be whitelisted? Here are some sensible rules for web site advertisingAn increasing number of websites are now detecting when users have ad-blocking enabled, and refuse to show content unless you "whitelist" their site (disable your ad-blocking for them). I think that is a fair decision on their part, it's how they pay for the site. However, if you want me (and many others) to white list your site, there are some rules you should follow. If you violate these rules, I won't whitelist your site, I'll just find content elsewhere. 1. The total space taken up by advertisements ...... 
  3. 12/30/2015Fantastic new series on Syfy called “The Expanse” – for people who love traditional science fiction[] “The Expanse” is a new science fiction series being broadcast onthe Syfy channelthis winter. It’s closely based on a series of books by author James S. A. Corey beginning with “Leviathan Wakes”. There are 5 books in the “Expanse” series so far. If you’re a fan of the novels you’ll appreciate how closely the books are followed.TIP: The first five episodes are already available on Syfy.com. If you’re having trouble getting into the characters and plot, use those to get up to speed.The worlds created for ...... 
  4. 10/20/2015My suggestion is to stay away from PayAnywhere(dot)com  
  5. 08/07/2015Here is one for you VMWARE gurus - particularly if you run ESXi without fancy drive arrays 
  6. 08/06/2015The Killer of Orphans (Orphan Documents) 
  7. 06/02/2015Homeopathic Marketing: Traveler on my Android is now calling itself VERSE. Allow me to translate that for the IBM Notes community... 
  8. 03/17/2015A review of British Airways Premium Economy Service – How to destroy customer goodwill all at once 
  9. 02/26/2015There's a bug in how @TextToTime() and @ToTime() process date strings related to international standards and browser settings. 
  10. 01/21/2015Delivering two new presentations at Developer Camp (EntwicklerCamp) 2015 in Germany 
Click here for more articles.....


pen icon Comment Entry
Subject
Your Name
Homepage
*Your Email
* Your email address is required, but not displayed.
 
Your thoughts....
 
Remember Me  

Please wait while your document is saved.