# Theme, timezone and currency

> Switch between light and dark, set the timezone that decides what today is, and pick the currency new accounts and budgets start in.

From Simple Balance: https://smpl.money/docs/preferences/. Updated 2026-10-25.


**Settings** opens on **Preferences**, where you choose whether Simple Balance
is light or dark, which timezone decides what day it is, and which currency new
accounts start in. None of these change a transaction you've already recorded.

## Switch between light and dark

1. Open **Settings**.
2. Under **Appearance**, choose **Light**, **Dark** or **Follow my system**.

The change happens as soon as you pick, with no button to press.
**Follow my system**, the starting choice, matches your device's light or dark
setting and changes when the device does. **Light** and **Dark** stay as they
are.

Your choice is saved to your account, so it comes back on any browser you sign
in from.

### The button in the sidebar

The moon or sun button at the bottom of the sidebar is a shortcut. It switches
to whichever of light and dark you aren't looking at.

If you're on **Follow my system**, pressing it sets **Light** or **Dark**, so
the app stops following your device. Choose **Follow my system** under
**Appearance** to go back.

## Set your timezone

Your timezone decides what day it is for Simple Balance. It's set from your
device the first time you sign in, so you may never need to change it.

1. Open **Settings**.
2. Under **Regional defaults**, choose your **Timezone**. Zones are listed by
   region and then city, so New York is under America. Each one shows its
   short name and how far it is from UTC today, like EDT (UTC-04:00) for New
   York in summer.
3. Press **Save preferences**. The app says **Preferences saved.**

### What your timezone changes

- **The date a new transaction starts on.** If the timezone were left on UTC,
  something you entered at 7 p.m. in California would start on tomorrow's
  date, because it's already tomorrow in UTC.
- **Where the date choices start and end**, like **This month** and
  **Last 30 days**.
- **Where figures stop.** The Overview, Reports and Budgets never count past
  today.
- **The day a recurring transaction comes due** and puts a row on Staged.
- **The day and time a template reminder email goes out.**
- **The times on [Activity history](https://smpl.money/docs/activity-history/)**, whatever
  device you're reading it on.

Changing your timezone doesn't move any transaction. Each one keeps the date it
already has.

## Choose your default currency

Your default currency is the one Simple Balance suggests when you make
something new.

1. Open **Settings**.
2. Under **Regional defaults**, choose from
   **Default account currency or crypto asset**. The list has every currency
   your browser knows, plus 14 crypto assets such as Bitcoin (BTC) and Ether
   (ETH).
3. Press **Save preferences**.

### What your default currency changes

- **A new account starts in it.** You can pick another currency on the form.
- **A new budget starts in it**, and you can pick another there too.
- **It comes first** on the Overview and in Reports, with any other currencies
  after it in alphabetical order.

It's only a starting point. It doesn't change the currency of an account you
already have, and nothing is ever converted.
[More than one currency](https://smpl.money/docs/multiple-currencies/) covers keeping accounts in
several.

## Set for you when you first sign in

The first time you sign in, Simple Balance sets your timezone from your device
and your currency from the country in your browser's language setting. English
(United States) gives US dollars and English (Canada) gives Canadian dollars.
If it can't tell, the currency starts on US dollars.

This only happens until a choice is saved, so it never replaces one you made.
If your device already matches where an account starts, UTC and US dollars,
nothing is saved, and it looks again the next time you open Simple Balance.
After that, only you change them, or an AI assistant you've allowed to.

## Changes an AI assistant can make

An AI assistant you've connected with **Read, stage, and commit** access can
change your timezone, your default currency and your theme. Every change to
your preferences, by you or by an assistant, is listed on
[Activity history](https://smpl.money/docs/activity-history/).
[Connecting an AI assistant](https://smpl.money/docs/agents-and-mcp/) covers what each kind of access allows.

## The rest of Settings

The same screen has **Connected agents**, covered in
[Connecting an AI assistant](https://smpl.money/docs/agents-and-mcp/), and **Sign-in methods**,
**Password** and **Delete this account**, covered in
[Your account and plan](https://smpl.money/docs/your-account-and-plan/). That page also covers
the **Plan and billing** tab.

On a self-hosted copy that doesn't sell plans, there's no
**Plan and billing** tab, only the preferences.