Files
freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/rosetta-code/date-manipulation.english.md
Josh Soref 004b99bf8f chore: fix typos in spelling (#38100)
* spelling: accidentally

* spelling: announce

* spelling: assembly

* spelling: avoid

* spelling: backend

* spelling: because

* spelling: claimed

* spelling: candidate

* spelling: certification

* spelling: certified

* spelling: challenge

* spelling: circular

* spelling: it isn't

* spelling: coins

* spelling: combination

* spelling: compliant

* spelling: containers

* spelling: concise

* spelling: deprecated

* spelling: development

* spelling: donor

* spelling: error

* spelling: everything

* spelling: exceed

* spelling: exist

* spelling: falsy

* spelling: faulty

* spelling: forward

* spelling: handle

* spelling: indicates

* spelling: initial

* spelling: integers

* spelling: issealed

* spelling: javascript

* spelling: length

* spelling: maximum

* spelling: minimum

* spelling: mutable

* spelling: notifier

* spelling: coordinate

* spelling: passport

* spelling: perform

* spelling: permuter

* spelling: placeholder

* spelling: progressively

* spelling: semantic

* spelling: submission

* spelling: submit

* spelling: translations

* spelling: turquoise

* spelling: visualization

* spelling: without

* spelling: registration

* spelling: representation
2020-02-08 23:59:10 +05:30

99 lines
3.2 KiB
Markdown

---
title: Date manipulation
id: 5966c21cf732a95f1b67dd28
challengeType: 5
forumTopicId: 302244
---
## Description
<section id='description'>
Given a date string in EST, output the given date as a string with 12 hours added to the time. Time zone should be preserved.
Example input: <code>"March 7 2009 7:30pm EST"</code>
Example output: <code>"March 8 2009 7:30am EST"</code>
</section>
## Instructions
<section id='instructions'>
</section>
## Tests
<section id='tests'>
```yml
tests:
- text: <code>add12Hours</code> should be a function.
testString: assert(typeof add12Hours === 'function');
- text: <code>add12Hours(dateString)</code> should return a string.
testString: assert(typeof add12Hours('January 17 2017 11:43am EST') === 'string');
- text: <code>add12Hours("January 17 2017 11:43am EST")</code> should return <code>"January 17 2017 11:43pm EST"</code>
testString: assert(add12Hours('January 17 2017 11:43am EST') === 'January 17 2017 11:43pm EST');
- text: Should handle day change. <code>add12Hours("March 7 2009 7:30pm EST")</code> should return <code>"March 8 2009 7:30am EST"</code>
testString: assert(add12Hours('March 7 2009 7:30pm EST') === 'March 8 2009 7:30am EST');
- text: Should handle month change in a leap years. <code>add12Hours("February 29 2004 9:15pm EST")</code> should return <code>"March 1 2004 9:15am EST"</code>
testString: assert(add12Hours('February 29 2004 9:15pm EST') === 'March 1 2004 9:15am EST');
- text: Should handle month change in a common years. <code>add12Hours("February 28 1999 3:15pm EST")</code> should return <code>"March 1 1999 3:15am EST"</code>
testString: assert(add12Hours('February 28 1999 3:15pm EST') === 'March 1 1999 3:15am EST');
- text: Should handle year change. <code>add12Hours("December 31 2020 1:45pm EST")</code> should return <code>"January 1 2021 1:45am EST"</code>
testString: assert(add12Hours('December 31 2020 1:45pm EST') === 'January 1 2021 1:45am EST');
```
</section>
## Challenge Seed
<section id='challengeSeed'>
<div id='js-seed'>
```js
function add12Hours(dateString) {
// Good luck!
return true;
}
```
</div>
</section>
## Solution
<section id='solution'>
```js
function add12Hours(dateString) {
const months = ['January', 'February', 'March', 'April', 'May', 'June',
'July', 'August', 'September', 'October', 'November', 'December'];
// Get the parts of the string
const parts = dateString.split(' ');
const month = months.indexOf(parts[0]);
const day = parseInt(parts[1], 10);
const year = parseInt(parts[2], 10);
const time = parts[3].split(':');
let hours = parseInt(time[0], 10);
if (time[1].slice(-2) === 'pm') {
hours += 12;
}
const minutes = parseInt(time[1].slice(0, -2), 10);
// Create a date with given parts, and updated hours
const date = new Date();
date.setFullYear(year, month, day);
date.setHours(hours + 12); // Add 12 hours
date.setMinutes(minutes);
let hoursOutput = date.getHours();
let abbreviation = 'am';
if (hoursOutput > 12) {
hoursOutput -= 12;
abbreviation = 'pm';
}
return `${months[date.getMonth()]} ${date.getDate()} ${date.getFullYear()} ${hoursOutput}:${date.getMinutes()}${abbreviation} EST`;
}
```
</section>