WordPress add_rewrite_rules for custom URLs ending in .html

You don’t need custom rewrites for that, you can simply use the permalinks settings to achieve those results. Click the Custom Structure option and enter:

/blog/%year%/%monthnum%/%postname%.html

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)