Issue
I want to change the timezone of my Heroku Postgres database.
Resolution
We highly suggest leaving your database times in UTC and modifying them at your application level. This results in your data being more ubiquitous and easier to convert when needed. Having dates in the database using a different timezone is problematic since many libraries and functions often expect dates and times in UTC.
If you need to change the timezone, you can connect to your Heroku Postgres database with $ heroku pg:psql and running ALTER DATABASE your_database_name SET timezone = timezone_name;. However, please consider the repercussions of changing the timezone for your application.
For example: ALTER DATABASE your_database_name SET timezone = 'Brazil / East';.
You can find the name of the different timezones recognised by PostgreSQL by running SELECT * FROM pg_timezone_names; on your database.