Admin: Regional settings in containers

Overview

Regional settings (locale, time zone, and currency formatting) are not managed by Kubernetes.

Instead:

• Kubernetes does not set currency or locale

• Each container determines regional settings at runtime

• Regional behavior depends on:

  • The base OS image

  • Installed locale packages

  • Environment variables

• Containers often default to UTC time zone

Time zone configuration

Time zone is typically set using the TZ environment variable.

Example (Docker Compose yaml):

services:
  app:
    image: my-dev-app
    environment:
      - TZ=UTC

Example (Kubernetes yaml):

env:
  - name: TZ
    value: UTC

Locale configuration

Locale determines:

• Number formatting

• Date formatting

• Currency formatting

• Character encoding

Common environment variables:

• LANG → default locale

• LC_ALL → overrides all locale categories

• LC_TIME → date/time formatting

• LC_MONETARY → currency formatting

Example:

environment:
  - LANG=en_US.UTF-8
  - LC_ALL=en_US.UTF-8

Currency behavior

There is no direct currency setting at the container level. Currency formatting depends on:

• Application runtime (.NET, Java, etc.)

• Active locale (en_US, fr_FR, etc.)

• Data type and formatting logic

Example:

• en_US → $1,000

• de_DE → 1.000,00 €

Locale must be installed in the image

The locale must be installed and generated inside the container image.

If it does not exists, you may see errors such as:

locale: Cannot set LC_ALL to default locale

When the above condition applies, the following steps can be used to enable locale:

RUN apt-get update && apt-get install -y locales \
    && echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen \
    && locale-gen

After this, locale-based commands should work as expected:

>  locale currency_symbol
# $

Workaround strategies

To avoid unintended global regional behavior, the following workaround can be applied at the application level.

1. Override regional date format

To prevent dates from being affected by system or container locale settings, use custom date formats instead of predefined formats such as:

• “Short date”

• “Long date”

• “Long date and time”

• These predefined formats depends on the active locale and may vary across environments.

• Common Date/Time Format Tokens

Examples:

MMM dd yyyy HH:mm:ss
→ Feb 06 2026 14:05:09

MM/dd/yyyy
→ 02/06/2026

dd-MM-yyyy
→ 06-02-2026

2. Override currency formatting

Currency formatting is typically driven by system locale or application settings. To avoid unintended currency changes, disable automatic currency formatting:

1. For decimal attributes, set number formatting to None.

2. 

   This prevents automatic application of a locale-based currency symbol.

3. Explicitly define currency in content instead of relying on system formatting:

   1. Manually prepend the currency symbol (e.g., $).

   2. Explicitly define the currency within the content or template.

      

      This ensures consistent display across environments regardless of locale.

3. Time zone

Currently, there is no application-level workaround for time zone differences.