The date on the permanent links is a practice derived from the creation of blogs many years ago. It identifies day, month and year in each URL in a numeric way.
The search engines previously recognized this date and took advantage of it in order to associate the age of the entry in the positioning. Until the publication identification was developed and Google showed the time that a news item was published. Here the matter began to get complicated. Some administrators chose to voluntarily change this date in order to make it appear older, others did it the other way around, to try to make it appear more current. They even modified the urls as time went by to take advantage of what they could. In practice, this turned out to be useless, because Google took care of identifying the exact date of publication by using the well-known sitemap file. With this measure, it was possible to identify the date of publication and, internally, the date of indexation.
Is the date still necessary in permanent links?
The answer is yes in a few cases. The URLs of the permanent links are an important SEO component, but this does not mean that among the options we have to configure its structure, we must necessarily choose the day, month and year. Instead, it is preferable to configure each url in a personalized way, for the SEO objectives we have with that particular page. In many occasions the title or H1 will help us to better define which permanent link we need in each page. But if this is not the case, we must make a decision.
If the date is decisive, such as in the case of events or product launches, then we must include it. To do this, however, we must choose the format ourselves. Sometimes we will only be interested in the year, other times it will be the month and the year, etc.
Depending on each situation we should set up a different and totally customized permanent link. Always, of course, that the date is a SEO factor in that publication. Therefore, the date structure in the permanent link is no longer as necessary as before, but its personalized inclusion will depend on the SEO needs we have each time.