Take a day off!

index.html

<h1>Take a Day Off!</h1>
<p>
  Behold, a random selection of workdays for you to take off over the next year.
</p>
<p>
  Now go do something fun with them!
</p>
<ol class="days"></ol>

script.js

const holidays = [
  [2018, 11, 12],   // Veteran's Day (Observed)
  [2018, 11, 22],   // Thanksgiving Day
  [2018, 11, 23],   // Thanksgiving Day-After Day
  [2018, 12, 25],   // Christmas Day
  [2019, 1, 1],     // New Year's Day
  [2019, 1, 15],    // Martin Luther King, Jr., Day
  [2019, 2, 18],    // President's Day
  [2019, 5, 27],    // Memorial Day
  [2019, 7, 4],     // Independence Day
  [2019, 9, 2],     // Labor Day
  [2019, 11, 11],   // Veteran's Day
  [2019, 11, 28],   // Thanksgiving Day
  [2019, 11, 29],   // Thanksgiving Day-After Day
  [2019, 12, 25]    // Christmas Day
]
.map(d => new Date(d[0], d[1] - 1, [d[2]]));

const isHoliday = (date) => {
  return holidays
    .map(holiday => holiday.getTime())
    .includes(date.getTime());
}

const isWeekend = (date) => {
  return [0, 6].includes(date.getDay());
}

const intoMonths = (acc, day) => {
  const m = day.getMonth();
  acc[m] = [...(acc[m] || []), day];
  return acc;
};

const intoFlattened = (acc, [firstDay, secondDay]) => {
  return acc.concat(firstDay, secondDay);
};

const intoHalves = (days) => {
  const mid = days.length / 2;
  return [days.slice(0, mid), days.slice(mid)];
};

const randomize = (items) => {
  return items.sort(() => {
    const randomCompare = Math.random() > Math.random();
    return randomCompare ? 1 : -1;
  });
};

const oneDay = 24 * 60 * 60 * 1000;
const today = new Date().getTime();

// Start with an array of 365 dates, beginning with today
const daysOff = new Array(365)
  .fill(null)
  .map((_, i) => new Date(new Date(today + (i * oneDay)).setHours(0, 0, 0, 0)))

  // Strip out holidays and weekends
  .filter(d => !isHoliday(d) && !isWeekend(d))

  // Group the remaining workdays into months
  .reduce(intoMonths, [])

  // Split each month into two arrays, one for the first half, one for the second
  .map(intoHalves)

  // Randomly select one day from each half of the month
  .map(month => month.map(d => randomize(d)))
  .map(([firstHalf, secondHalf]) => [...firstHalf.slice(-1), ...secondHalf.slice(-1)])

  // And finally, flatten, re-sort by date, and return the list
  .reduce(intoFlattened, [])
  .sort((a, b) => a < b ? -1 : 1);

// Enjoy!
document.addEventListener('DOMContentLoaded', () => {
  const days$ = document.querySelector('.days');
  
  daysOff.forEach(day => {
    const day$ = document.createElement('li');
    day$.innerText = day;
    days$.appendChild(day$);
  });
});

style.css

body {
  font-family: Helvetica, sans-serif;
  font-size: 14px;
  line-height: 18px;
}

.date {
  
}

take-a-day-off.markdown

Take a day off!

A Pen by Christian Nunciato on CodePen.

License.