You have the liberty to change the dates of your posts as well as archive pages by going through the setting of your site. The first thing you need to do is to Go to Blogger.com >> your site >> Layout >> Post body >> Edit.
On pressing the “Edit” link, a new window will pop out which would display quite a few of options. Now just under the “Post Page Options” change the format of your dates. By default, it only displays the time when your article was published, so from the drop down list select the most appropriate date format. Once everything is done press the save button located at the bottom of the page.
Congratulations: You have successfully updated the format of the date of your posts.
This probably won’t help you in improving your SEO rankings as they are just for the betterment for the user experience. Being a blogger, you should keep your content up-to-date this would not help you to increase your credibility, but it will also help you in gaining the trust of your users.
Removing Dates from your posts is something that should not be practiced by anyone. There are few so-called SEO consultants that just think that Google fetches the dates from a simple piece of HTML Code. Google gets the dates from your sitemap. So what are your thoughts? Any suggestions that you may have?