CODEWITHSUNDEEP
javascriptdate
NEOJPK
NEOJPK

Reputation: 833

how to get the nearest decade/century/millenium with javascript

im trying to find a way to get the 2 nearest ranges of a date could be decade , century, millenium

Example

var date = new Date() // Mon Jul 09 2018 17:12:17 GMT-0400
date.getDecadeRange() // [Jan 01 2010 , Dec 31 , 2019]

And so on.

Upvotes: 1

Views: 1969

Answers (2)

Jonas Wilms
Jonas Wilms

Reputation: 138457

To round to the closest multiple we might use small utility:

 const round = (n, to) => n - n % to;

Now we just have to round the years, and take the first day:

const round = (n, to) => n - n % to;

const now = new Date();

const start = new Date(round(now.getFullYear(), 100), 0, 1);
// Go to the start of the next period ...
const end = new Date(round(now.getFullYear(), 100) + 100, 0, 1);
end.setDate(end.getDate() - 1); // then go one day back

console.log(`${start}\n${end}`);

Upvotes: 4

NEOJPK
NEOJPK

Reputation: 833

Thanks everyone who answered. reading the jonas answer i had a momento and it came up to me the answer

const dateRanges = (date, rule, sum = 0) 
      => Math.floor(date.getFullYear() / rule) * rule + sum

And i can execute it in this way

const lowerDecade  = dateRanges(new Date() , 10 /** => decade**/)
const upperDecade  = dateRanges(new Date() , 10 /** => decade**/, 9)

Upvotes: 1

Related Questions