getQuarter

1/**
2 * Returns the quarter (1–4) of the given date.
3 *
4 * @param date - The date to evaluate.
5 * @returns A number representing the quarter (1 to 4).
6 *
7 * @example
8 * getQuarter(new Date('2024-02-15')) // 1
9 * getQuarter(new Date('2024-06-01')) // 2
10 */
11export function getQuarter(date: Date): number {
12  return Math.floor(date.getMonth() / 3) + 1;
13}

1test('returns Q1 for January', () => {
2  expect(getQuarter(new Date('2024-01-01'))).toBe(1);
3});
4
5test('returns Q2 for May', () => {
6  expect(getQuarter(new Date('2024-05-10'))).toBe(2);
7});
8
9test('returns Q3 for August', () => {
10  expect(getQuarter(new Date('2024-08-20'))).toBe(3);
11});
12
13test('returns Q4 for December', () => {
14  expect(getQuarter(new Date('2024-12-25'))).toBe(4);
15});