get the date for the first day of the current decade in typescript

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

const today = new Date();
const firstDayOfDecade = startOfDecade(today);

console.log(firstDayOfDecade); // Output: {Date Object for the first day of current decade}
209 chars
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index.ts
import moment from 'moment';

const today = moment();
const firstDayOfDecade = today.startOf('decade');

console.log(firstDayOfDecade); // Output: {Moment.js Object for the first day of current decade}
202 chars
7 lines