As you should know, Grav is a flat file system CMS. This means the application does not require a database to work.
When you need to add a new blog post, you just need to create a folder and add a new file inside it. When you have your file, you can open it and add it your contents. Nice and easy!
The blog post you just created, uses as its page url, the folder name. Hopefully that name is quite long, briefs the post content and contains some useful seo keywords.
A real world example would look like this one:
blog add-the-posts-categories-to-our-blog-navigation-menu-powered-by-grav-cms item.md img.jpg blog-posts-schedulation-with-grav-cms item.md img.jpg efficient-way-to-properly-name-blog-posts-folders-for-a-grav-cms-blog item.md img.jpg how-to-configure-a-grav-cms-plugin-overriding-its-configuration item.md img.jpg
This works very well until you have few entries, but, while your blog grows, it would be always more difficult to find a particular post, or just the last one you have started to written yesterday. This happens because post folders are not ordered by date but by name.
To start giving a better organization to your blog posts, you could add some non-written rules to yourself, to keep thinks organized:
YYMMDDrule. This means two digits for the year, two for the month, two for the day.
In this way posts are well ordered in your folder by date and, thanks to the brief description, you are able to immediately recognize the topic of your post.
After applying those rules, the previous example will result as follows:
blog 150801-grav-navigate-through-categories item.md slug: add-the-posts-categories-to-our-blog-navigation-menu-powered-by-grav-cms img.jpg 150802-grav-posts-schedulation item.md slug: blog-posts-schedulation-with-grav-cms img.jpg 150803-plugin-configuration item.md slug: how-to-configure-a-grav-cms-plugin-overriding-its-configuration img.jpg 150804-blog-folders-name item.md slug: efficient-way-to-properly-name-blog-posts-folders-for-a-grav-cms-blog img.jpg
Obviously those rules are not written in the stone, so you can customize them as you prefer. You may want to have an eight digits date and keep the full slug in the title. In this case, the blog folder will look as follows:
blog 20150801-add-the-posts-categories-to-our-blog-navigation-menu-powered-by-grav-cms item.md slug: add-the-posts-categories-to-our-blog-navigation-menu-powered-by-grav-cms img.jpg 20150802-blog-posts-schedulation-with-grav-cms item.md slug: blog-posts-schedulation-with-grav-cms img.jpg 20150803-efficient-way-to-properly-name-blog-posts-folders-for-a-grav-cms-blog item.md slug: efficient-way-to-properly-name-blog-posts-folders-for-a-grav-cms-blog img.jpg 20150804-how-to-configure-a-grav-cms-plugin-overriding-its-configuration item.md slug: how-to-configure-a-grav-cms-plugin-overriding-its-configuration img.jpg
What you should really leave unchanged is the format order, which must always be Year, Month, Day and both month and day must be represented by two digits. All the other situations would produce a bad ordering result.