the_modified_date returns published date

I think that you are using Parsidate plugin to convert dates to Hijri date. The plugin since the current version(2.2.2) returns the published date for both the_date and the_modified_date functions. This is a bug that i reported it to them. For now, you can use the wp-jalali plugin instead, that solved the problem for me.

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