@stdlib/time/iso-weeks-in-year/README.md

Time utilities.

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# isoWeeksInYear

> Determine the number of [ISO weeks][iso-week-date] in a year according to the [Gregorian calendar][gregorian-calendar].

<section class="usage">

## Usage

```javascript
var isoWeeksInYear = require( '@stdlib/time/iso-weeks-in-year' );
```

#### isoWeeksInYear( \[value] )

Returns the number of [ISO weeks][iso-week-date] in a year according to the [Gregorian calendar][gregorian-calendar].

```javascript
var num = isoWeeksInYear();
// returns <number>
```

By default, the function returns the number of [ISO weeks][iso-week-date] in the current year (according to local time). To determine the number of [ISO weeks][iso-week-date] for a particular year, provide either a year or a [`Date`][date-object] object.

```javascript
var num = isoWeeksInYear( new Date() );
// returns <number>

num = isoWeeksInYear( 2015 );
// returns 53

num = isoWeeksInYear( 2017 );
// returns 52
```

</section>

<!-- /.usage -->

<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var isoWeeksInYear = require( '@stdlib/time/iso-weeks-in-year' );

var v;
var i;

for ( i = 0; i < 2021; i++ ) {
    v = isoWeeksInYear( i );
    console.log( 'The year %d has %d ISO weeks.', i, v );
}
```

</section>

<!-- /.examples -->

* * *

<section class="cli">

## CLI

<section class="usage">

### Usage

```text
Usage: iso-weeks-in-year [options] [year]

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.
```

</section>

<!-- /.usage -->

<section class="examples">

### Examples

```bash
$ iso-weeks-in-year
<number>
```

For a specific year,

```bash
$ iso-weeks-in-year 2015
53
```

</section>

<!-- /.examples -->

</section>

<!-- /.cli -->

<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->

<section class="related">

</section>

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<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->

<section class="links">

[iso-week-date]: https://en.wikipedia.org/wiki/ISO_week_date

[gregorian-calendar]: https://en.wikipedia.org/wiki/Gregorian_calendar

[date-object]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date

</section>

<!-- /.links -->