How to remove the date from wordpress posts

I would like to remove the date from my posts because of my evergreen content. I have everything organized in categories, but most of it looks outdate since the posts are few months old, nevertheless the content is up to date.

I tryed removing the date under Apperance -> Edit CSS with the following code:

.entry-date {
display: none;
}

It does not work. Can you help please?