[ui, docs] add custom play time formatting

Signed-off-by: codeman4033 <codeman4033@eden-emu.dev>

docs/user/CustomPlayTime.md

@@ -0,0 +1,167 @@
+# Custom Play Time Syntax
+
+This document describes the formatting syntax used to display custom playtime values in the emulator.
+
+## Overview
+
+Playtime is internally stored as a total number of seconds. This formatting system allows users to control how that value is displayed by using tokens inside a format string.
+
+Example:
+
+```
+{H:02}:{M:02}:{S:02}
+```
+
+Output:
+
+```
+02:03:04
+```
+
+## Tokens
+
+The following tokens can be used in format strings.
+
+| Token | Description              |
+| ----- | ------------------------ |
+| `{d}` | Total days               |
+| `{h}` | Total hours              |
+| `{H}` | Hours component (0–23)   |
+| `{m}` | Total minutes            |
+| `{M}` | Minutes component (0–59) |
+| `{s}` | Total seconds            |
+| `{S}` | Seconds component (0–59) |
+
+## Padding
+
+Tokens may optionally include zero-padding using the syntax `:NN`, where `NN` is the minimum width.
+
+Example:
+
+```
+{H:02}:{M:02}:{S:02}
+```
+
+This ensures each component is displayed with at least two digits.
+
+Example output:
+
+```
+02:03:04
+```
+
+## Conditional Sections
+
+Conditional sections allow parts of the format string to appear only when a specific time unit is non-zero. This is useful for hiding units such as `0h`.
+
+Conditional sections use the following syntax:
+
+```
+[unit] ... [/unit]
+```
+
+Where `unit` is one of the following:
+
+| Unit | Condition                      |
+| ---- | ------------------------------ |
+| `d`  | Display section if days > 0    |
+| `h`  | Display section if hours > 0   |
+| `m`  | Display section if minutes > 0 |
+
+Example:
+
+```
+[h]{H}h [/h][m]{M}m [/m]{S}s
+```
+
+Possible outputs:
+
+```
+1h 3m 4s
+3m 4s
+4s
+```
+
+Conditional sections may contain both tokens and literal text.
+
+## Escaping Braces
+
+To include literal braces in the output, they must be escaped using double braces.
+
+| Input | Output |
+| ----- | ------ |
+| `{{`  | `{`    |
+| `}}`  | `}`    |
+
+Example:
+
+```
+Playtime: {{ {H}:{M}:{S} }}
+```
+
+Output:
+
+```
+Playtime: { 2:3:4 }
+```
+
+## Literal Text
+
+Any text outside of tokens or conditional sections is copied directly into the output.
+
+Example:
+
+```
+{h}h {M}m {S}s
+```
+
+Output:
+
+```
+26h 3m 4s
+```
+
+## Examples
+
+### Clock Format
+
+```
+{H:02}:{M:02}:{S:02}
+```
+
+Example output:
+
+```
+02:03:04
+```
+
+### Human Readable Format
+
+```
+{h} hours, {M} minutes, {S} seconds
+```
+
+Example output:
+
+```
+26 hours, 3 minutes, 4 seconds
+```
+
+### Compact Format
+
+```
+[h]{H}h [/h][m]{M}m [/m][s]{S}s
+```
+
+Example output:
+
+```
+3m 4s
+```
+
+## Notes
+
+* Playtime values are derived from the total number of elapsed seconds.
+* Component tokens (`H`, `M`, `S`) wrap within their normal ranges.
+* Total tokens (`h`, `m`, `s`) represent the full accumulated value for that unit.
+* This is based on the [fmt syntax](https://fmt.dev/12.0/syntax/). Almost everything there is also supported here.

docs/user/README.md

@@ -9,7 +9,7 @@ A copy of this handbook is [available online](https://git.eden-emu.dev/eden-emu/
 ## Basics
 
 - **[The Basics](Basics.md)**
-- **[Quickstart](./QuickStart.md)**
+- **[Quickstart](QuickStart.md)**
 - **[Settings](./Settings.md)**
 - **[Controllers](./Controllers.md)**
     - **[Controller profiles](./Controllers.md#configuring-controller-profiles)**
@@ -26,6 +26,7 @@ A copy of this handbook is [available online](https://git.eden-emu.dev/eden-emu/
 - **[Installing Atmosphere Mods](./InstallingAtmosphereMods.md)**
 - **[Installing Updates & DLCs](./InstallingUpdatesDLC.md)**
 - **[Alter Date & Time](./AlterDateTime.md)**
+- **[Custom Play Time Syntax](./CustomPlayTime.md)**
 
 ## 3rd-party Integration