301 Redirect all posts urls from .html to / (without .html)

Question

How can i redirect all posts permalinks from .html to / ,in Wordpress ? now all my posts url are ending in / ,but before it was with .html

to be more clear ,for example a post url like this http://sitename.com/%category%/%postname%.html to be redirected to http://sitename.com/%year%/%monthnum%/%postname%/ . It's simple to redirect them one by one,but i need a rule to redirect all posts .

my curent .htaccess

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

======

Thank you

Answer 1

it's curious that redirect_canonical doesn't work in this case, but this will redirect everything with .html via .htaccess:

RewriteRule (.+)\.html?$ http://example.com/$1/ [R=301,L]

but keep in mind this will redirect everything with .html, you may need to explicitly exclude things.

Answer 2

That's strange. I thought WordPress did that automatically. Here's the default one that WordPress generated for me:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

Try that on for size. Note how this one includes <IfModule mod_rewrite.c> and </IfModule>