---
id: 5900f37f1000cf542c50fe92
challengeType: 5
title: 'Problem 19: Counting Sundays'
videoUrl: ''
localeTitle: ''
---

## Description
undefined

## Instructions
undefined

## Tests
<section id='tests'>

```yml
tests:
  - text: ''
    testString: 'assert.strictEqual(countingSundays(1943, 1946), 6, "<code>countingSundays(1943, 1946)</code> should return 6.");'
  - text: ''
    testString: 'assert.strictEqual(countingSundays(1995, 2000), 9, "<code>countingSundays(1995, 2000)</code> should return 9.");'
  - text: ''
    testString: 'assert.strictEqual(countingSundays(1901, 2000), 171, "<code>countingSundays(1901, 2000)</code> should return 171.");'

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='js-seed'>

```js
function countingSundays(firstYear, lastYear) {
  // Good luck!
  return true;
}

countingSundays(1943, 1946);

```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```
</section>