CODEWITHSUNDEEP
javascript
JohnnyJS
JohnnyJS

Reputation: 1472

Get Years Months and days from days

I seem to not be getting it. I have number of days, say 762 which will be 2 years(730 days each 365 days), 1 month(762-730), and 2 days(assuming every month has constant 30 days)

I need to do that on JS. this what I came up with:

days = 762;
ymd = {
    d: days % 30,
    m: Math.floor((days - (days % 30)) / 30),
    y: ((days - (days % 365)) / 365),
}
if (ymd.m > 12){
    ymd.y += Math.floor(ymd.m / 12);
    ymd.m =  ymd.m % 12;
}
console.log(ymd);

Well it's not working.

Upvotes: 1

Views: 201

Answers (2)

Paul S.
Paul S.

Reputation: 66394

Using your assumptions on year/month lengths;

function dToYMD(i) {
    var y, m ,d;
    y = (i / 365) | 0;
    i = i - y * 365;
    m = (i /  30) | 0;
    i = i - m *  30;
    d =  i        | 0;
    return [y, m, d];
}
dToYMD(762); // [2 /* years */, 1 /* month */, 2 /* days */]

I thought there was something built in. i meant using Date obj

This would not use your assumptions for lengths, but you could set a date based upon the unix epoch, and then minus 1970 from the year.

function dToYMD(i) {
    var d = new Date(i * 864e5);
    return [d.getUTCFullYear() - 1970, d.getUTCMonth(), d.getUTCDate() - 1];
}
dToYMD(762); // [2 /* years */, 1 /* month */, 1 /* days */]

Note this time, the number of days is different because January has 31 days.

Upvotes: 3

eazimmerman
eazimmerman

Reputation: 609

Modulus (%) returns the remainder after a division. You should be using regular division then flooring the value.

Like so:

var numOfDays = 762;

var years = Math.floor(numOfDays / 365),
    months = Math.floor((numOfDays-(years*365)) / 30),
    days = ((numOfDays-(years*365))-months*30);

Here is the working code

Upvotes: 1

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