CODEWITHSUNDEEP
javascriptmomentjs
Kinji
Kinji

Reputation: 51

Moment check next month

I'd like to check the date if it's next month from the current.

Some test cases here

2020.1.1 2019.12.30 // true

2019.11.30 2019.10.10 // true

2019.12.11 2019.12.1 // false

So as you can see, I'd like to check if the date is next month from now.

Hope to get the brilliant idea! Best Kinji

Upvotes: 0

Views: 748

Answers (2)

Terry Lennox
Terry Lennox

Reputation: 30675

You could try this approach, we have to handle the case when the dates are in the same year and also for December and January of the next year.

A simple algorithm can be created, whereby we multiply the year by 12, add the month and get the difference of this score between the two dates. As long as the value of this is 1 or -1 we have months that are adjacent. I'm presuming you only need to check if the first parameter is the next month to the second parameter, so we check for a difference of 1. 

function isNextMonth(timeStamp1, timeStamp2, format = "YYYY.MM.DD") {
  let dt1 = moment(timeStamp1, format);
  let dt2 = moment(timeStamp2, format);
  return ((dt1.year()*12 + dt1.month() - dt2.year()*12 - dt2.month()) === 1);
}

let inputs = [['2020.1.1','2019.12.30'],['2019.11.30', '2019.10.10'], ['2019.12.11','2019.12.1'], ['2020.12.1','2021.1.1'], ['2020.6.1','2020.5.1'],  ['2021.1.1','2019.12.1'], ['2019.3.1', '2019.4.1']];
for(let [inputa, inputb] of inputs) { 
    console.log(`isNextMonth(${inputa}, ${inputb}): ${isNextMonth(inputa, inputb)}`);
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.min.js"></script>

Upvotes: 2

Aron B.
Aron B.

Reputation: 281

A very simple solution would be to use Moment’s isSame. This only checks the month. If you also want to make sure that the year matches you would have to make sure that nextMonth.getYear() matches dateToCheck.getYear()

var dateToCheck = new Date(2019, 11, 30)
var nextMonth = new Date()
nextMonth.setMonth(dateToCheck.getMonth() + 1)
moment(dateToCheck).isSame(nextMonth, 'month');

Upvotes: 0

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