# Date and Number Extensions

Date-part getters, the `$format` formatter, and relative time on `Date.prototype`, plus timestamp and random-key helpers on `Number.prototype`.

## Date

Source: `src/prototype/Date.ts`

| Method / Property | Description |
| --- | --- |
| `date.$y` / `$yy` / `$yyyy` | Year (raw, 2-digit, 4-digit) |
| `date.$M` / `$MM` | Month, 1-indexed (raw, zero-padded) |
| `date.$D` / `$DD` | Day of month (raw, zero-padded) |
| `date.$d` / `$dd` / `$ddd` / `$dddd` | Day of week: index, then localized name at increasing length (English abbreviations or 星期X in `zh` locales, detected via `navigator.language`) |
| `date.$H` / `$HH` | 24-hour hour (raw, zero-padded) |
| `date.$h` / `$hh` | 12-hour hour (raw, zero-padded) |
| `date.$a` / `$A` | `am`/`pm` (lower/upper case) |
| `date.$m` / `$mm` | Minutes (raw, zero-padded) |
| `date.$s` / `$ss` | Seconds (raw, zero-padded) |
| `date.$S` / `$SS` / `$SSS` | Milliseconds, sliced to 1/2/3 digits |
| `date.$timestamp` | Unix timestamp in seconds |
| `date.$gone` | Humanized relative time (`"3 days"` / `"3天"`, `"Coming in..."` / `"還有..."`, `"recent"` / `"剛剛"` for < 1 minute), localized by `navigator.language` |
| `date.$format(format = "yyyy/MM/DD (ddd) HH:mm:ss")` | Token-based formatter; supports `Y`/`M`/`D`/`H`/`h`/`m`/`s`/`S`/`A`/`a`/`d` tokens at the repeat-counts shown above |
| `date.$date(body?)` | Given `{ start }` / `{ end }` / `{ pre: { start } }` / `{ pre: { end } }`, returns the first/last day of the current or previous month; otherwise `new Date()` |

## Number

Source: `src/prototype/Number.ts`

| Method / Property | Description |
| --- | --- |
| `n.$uniKey` | Random string of length `n`, drawn from a 52-character alphabet, deduplicated against previously generated keys for the process lifetime |
| `n.$ASCII` | `String.fromCharCode(n)` |
| `n.$date` | Treats `n` as a Unix timestamp (seconds) and returns the corresponding `Date` |
| `n.$y` / `$M` / `$D` / `$d` / `$H` / `$h` / `$a` / `$A` / `$m` / `$s` / `$S` (and their padded/repeated variants) / `$gone` | Forwarded to `n.$date`'s equivalent `Date` getter |
| `n.$format(format)` | Forwarded to `n.$date.$format(format)` |