Luxon has start of day, year, etc., but how to find the first day of the decade?
You can use the below code to achieve your purpose:
document.addEventListener('DOMContentLoaded', function() {
const {
DateTime
} = luxon;
// Get the current DateTime
const now = DateTime.local();
// Calculate the first year of the decade
const firstYearOfDecade = now.year - (now.year % 10);
// Create a new DateTime object with the first year of the decade, first month, and first day
const firstDayOfDecade = DateTime.local(firstYearOfDecade, 1, 1);
// You can use it print whatever you like
console.log(`${firstDayOfDecade.toISODate()} - ${firstDayOfDecade.weekdayLong}`);
});
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