How to find out when a website was published?

TL;DR:
In order to find out the approximate date when a website was published you have to:
1. Search the URL in Google.
2. Add &as_qdr=y15 at the end of the URL showing up in your browser bar after searching and then hit enter.
3. The date will appear to the left of the search result.

When I worked at an agency, a colleague from the social media department came once to the SEO department to ask how he could find out the publishing date of some page if it was not specified in the content itself.

First thing that came to our minds was some of the traditional methods.

• The date of the first comments.

• The dates that some CMSs add to the URL.

• The structured data that some times got added automatically through, for example, some WordPress plugins or themes.

The problem with those solutions was that they don’t work in many cases (it can happen that there is no date in the URL or no structured data was added) or the date was inexact (the first comment can be placed a few months after the real publishing date).

So, out of curiosity, I started to search the internet for a more reliable method to find out the date. I don’t remember where I found it but at the time of writing I have searched it again and found many resources mentioning it (sample 1, sample 2).

How to do it?

The method is quite simple and it uses Google search results to obtain the information. It consists in adding a text snippet to the URL appearing in the browser bar after searching the URL of the specific page. Example:

I want to know the publishing date of this page.

1. I paste the page URL in Google and do a search. A normal search result page will show up.

2. I paste the following text snippet at the end of the URL in the browser bar and then hit enter.

&as_qdr=y15

3. A new search results page will appear but this time including a date near the result:

What does it mean?

It’s difficult to know it certainly but the date that Google shows after adding the snippet to the URL very often coincides with the publishing date so it could be the indexation date, but I’m not sure about that.

When adding the snippet to the end of the URL we are actually setting a new parameter with as_qdr as a value and y15 as a key.

Doing a normal use of Google, a similar parameter is added to the URL when we filter the search results by date.

The difference, in this case, would be that the key is tbs and the value qdr😡, where x equals the time dfined in the filter.

• Past hour → tbs=qdr:h
• Past 24 hours → tbs=qdr:d
• Past week → tbs=qdr:w
• Past month → tbs=qdr:m
• Past year → tbs=qdr:y

If we add a number after the final letter of the parameter we would be defining the number of time units that we want to set in the filter.

• tbs=qdr:h15 → Past 15 hours
• tbs=qdr:w15 → Past 15 weeks
• tbs=qdr:y15 → Past 15 years

So, what we are actually doing by adding the parameter &as_qdr=y15 is defining a period of 15 years in the filter:

It looks like the filter period does not have to be 15 years specifically for the date to show up, it only needs to be older than the date associated to the page.

In other words, if the page of the example was indexed in April 2018 and this was written in September 2018, it would be enough to add a period of 6 months to the filter for the date to show up:

The reason why this method is recommended everywhere with the 15 years filter is probably to use a big timeframe just in case the page we are investigating is very old.

However, if we wanted to set an even bigger timeframe we could extend the filter up to 19 years, which seems to be the maximum period that shows the date. If we go further than 20 it stops working:

When it may not work?

As long as I have been able to see, the method fails in the following situations:

• If G does not index the page immediately because it has a low authority or it is nor properly linked so it takes longer for it to be discovered.
• If the page has been substantially modified, it reindexes it and changes the date showing up in the search results.
• If a date is shown in the content and it’s incorrect (it does not coincide with the real publishing date), the date shown when adding the parameter could be the incorrect one.
• If the page has a high authority or relevancy then it will be reindexed often even if no significant changes take place. Example: the Donald Trump Wikipedia page shows a recent date when adding the parameter, but according to the revision history no important changes have been made to the content since long ago.
• Sometimes it just fails without any apparent reason. Sample.