how to use the differenceinisoweekyears function from the date-fns library in typescript

To use the differenceInISOWeekYears function from the date-fns library in TypeScript, you must first install the library using the following command:

index.ts
npm install date-fns
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After that, you can import the library and use the differenceInISOWeekYears function as shown below:

index.ts
import { differenceInISOWeekYears } from 'date-fns';

const date1 = new Date(2010, 6, 2);
const date2 = new Date(2012, 6, 2);

const difference = differenceInISOWeekYears(date1, date2);
console.log(difference); // expected output: 1
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Here, we import the differenceInISOWeekYears function from the date-fns library and use it to calculate the difference between two dates date1 and date2 in ISO week years. The difference variable then holds the difference in ISO week years between the two dates, which is 1 in this case.

This function calculates the difference in ISO week years, which are based on the ISO calendar, where each week has 7 days and week 1 of any year is the week containing January 4. This means that the first week of the year may contain days from the previous year and the last week of the year may contain days from the following year.