Add docs about missing timezones in MySQL/MariaDB

docs/advanced_usage.md

@@ -517,6 +517,31 @@ existing tables) with:
     an older system may fix issues that can arise while setting up Paperless-ngx but
     `utf8mb3` can cause issues with consumption (where `utf8mb4` does not).
 
+
+### Missing timezones
+
+Django uses timezones but MySQL as well as MariaDB do not have any timezone information by default.
+
+This results in not being able to filter by date ranges (i.e. using after/before in the "Created" or "Added" filters).
+
+To fix that, you have to add the timezone information into your database by using one of the following commands depending on whether you are using MySQL or MariaDB.
+
+Note: In case you are using the official MariaDB docker image, this is already done while initializing the database.
+
+To check whether an import of the timezone information is necessary, you can take a look into the `time_zone` table inside the `mysql` database. If this table is empty, you have to import the timezone information using the commands bellow.
+
+MySQL (and older MariaDB installations):
+
+```
+mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root mysql -p
+```
+
+MariaDB:
+
+```
+mariadb-tzinfo-to-sql /usr/share/zoneinfo | mariadb -u root mysql -p
+```
+
 ## Barcodes {#barcodes}
 
 Paperless is able to utilize barcodes for automatically performing some tasks.