timeSinceUntil

1/**
2 * Returns the time difference between two dates in absolute or directional mode.
3 * If `since` is true, it returns time elapsed from the past date to now.
4 * If `since` is false, it returns time remaining from now to a future date.
5 *
6 * If the direction doesn't match the dates, returns all zeros.
7 *
8 * @param date - The target date for comparison.
9 * @param since - Whether to measure time since or until the date.
10 * @returns An object with time components (days, hours, etc.).
11 */
12export function timeSinceUntil(
13  date: Date,
14  since: boolean
15): {
16  days: number;
17  hours: number;
18  minutes: number;
19  seconds: number;
20  milliseconds: number;
21} {
22  const now = new Date();
23  const diff = (since ? now.getTime() - date.getTime() : date.getTime() - now.getTime());
24
25  if (diff <= 0) {
26    return { days: 0, hours: 0, minutes: 0, seconds: 0, milliseconds: 0 };
27  }
28
29  const msInSecond = 1000;
30  const msInMinute = msInSecond * 60;
31  const msInHour = msInMinute * 60;
32  const msInDay = msInHour * 24;
33
34  let remaining = diff;
35
36  const days = Math.floor(remaining / msInDay);
37  remaining %= msInDay;
38
39  const hours = Math.floor(remaining / msInHour);
40  remaining %= msInHour;
41
42  const minutes = Math.floor(remaining / msInMinute);
43  remaining %= msInMinute;
44
45  const seconds = Math.floor(remaining / msInSecond);
46  const milliseconds = remaining % msInSecond;
47
48  return { days, hours, minutes, seconds, milliseconds };
49}

1test('timeSinceUntil - time since 1d 2h 30m 20s 500ms ago', () => {
2  const now = new Date();
3  const past = new Date(now.getTime() -
4    1 * 24 * 60 * 60 * 1000 -    // 1 day
5    2 * 60 * 60 * 1000 -         // 2 hours
6    30 * 60 * 1000 -             // 30 minutes
7    20 * 1000 -                  // 20 seconds
8    500                         // 500 ms
9  );
10
11  const result = timeSinceUntil(past, true);
12
13  expect(result.days).toBe(1);
14  expect(result.hours).toBe(2);
15  expect(result.minutes).toBe(30);
16  expect(result.seconds).toBe(20);
17  expect(result.milliseconds).toBeGreaterThanOrEqual(490);
18  expect(result.milliseconds).toBeLessThanOrEqual(510);
19});
20
21test('timeSinceUntil - future date with "since" returns all zeros', () => {
22  const future = new Date(Date.now() + 5000);
23  expect(timeSinceUntil(future, true)).toEqual({
24    days: 0,
25    hours: 0,
26    minutes: 0,
27    seconds: 0,
28    milliseconds: 0,
29  });
30});
31
32test('timeSinceUntil - time until 1h 5m 20s 300ms from now', () => {
33  const future = new Date(Date.now() +
34    1 * 60 * 60 * 1000 +         // 1 hour
35    5 * 60 * 1000 +              // 5 minutes
36    20 * 1000 +                  // 20 seconds
37    300                         // 300 ms
38  );
39
40  const result = timeSinceUntil(future, false);
41
42  expect(result.days).toBe(0);
43  expect(result.hours).toBe(1);
44  expect(result.minutes).toBe(5);
45  expect(result.seconds).toBe(20);
46  expect(result.milliseconds).toBeGreaterThanOrEqual(290);
47  expect(result.milliseconds).toBeLessThanOrEqual(310);
48});