Function setMonth

setMonth(date: Date, month: number): Date
Sets the month of the given date (1-based, e.g. 1 = January) and returns a new Date instance.
Parameters
- date: Date
  The original date.
- month: number
  The month to set (1–12).
Returns Date
A new Date with the updated month.
Example
```
setMonth(new Date('2025-01-01'), 12); // → 2025-12-01
```
- Defined in date/set.ts:27