How to Select Min/Max Dates in an Array Using JavaScript?

Here are the different ways to select min/max dates in an array using JavaScript

1. Using Math.max and Math.min

Use Math.max and Math.min function to get the maximum and minimum dates respectively.

let dates = [
    new Date("2019/06/25"),
    new Date("2019/06/26"),
    new Date("2019/06/27"),
    new Date("2019/06/28")
];

function fun() {
    const maxDate = new Date(Math.max(...dates));
    const minDate = new Date(Math.min(...dates));

    console.log("Max date is - " + maxDate);
    console.log("Min date is - " + minDate);
}

fun();

Max date is - Fri Jun 28 2019 00:00:00 GMT+0000 (Coordinated Universal Time)
Min date is - Tue Jun 25 2019 00:00:00 GMT+0000 (Coordinated Universal Time)

In this example:

• The code finds the maximum (latest) and minimum (earliest) dates from an array of Date objects.
• It uses Math.max() and Math.min() with the spread operator (...) to get the highest and lowest timestamps, and then converts them back to Date objects.
• The result is printed using console.log().

2. Using reduce() method

Use reduce() method in an array of dates and define the respective function for the maximum and minimum dates.

let dates = [
    new Date("2019/06/25"),
    new Date("2019/06/26"),
    new Date("2019/06/27"),
    new Date("2019/06/28")
];
function fun() {
    const minDate = dates.reduce((a, b) => (a < b ? a : b));
    const maxDate = dates.reduce((a, b) => (a > b ? a : b));

    console.log("Max date is - " + maxDate);
    console.log("Min date is - " + minDate);
}
fun();

Max date is - Fri Jun 28 2019 00:00:00 GMT+0000 (Coordinated Universal Time)
Min date is - Tue Jun 25 2019 00:00:00 GMT+0000 (Coordinated Universal Time)

In this example:

• The code uses reduce() to iterate through the dates array, comparing two dates (a and b) at a time. It finds:
• Minimum date (minDate): By keeping the smaller of a and b.
• Maximum date (maxDate): By keeping the larger of a and b.

3. Using Spread Operator

To select the minimum and maximum dates in an array, use the spread operator to clone the array.

let dates = [new Date('2022-01-01'), new Date('2022-03-15'), new Date('2022-02-10')];
let minDate = new Date(Math.min(...dates));
let maxDate = new Date(Math.max(...dates));
console.log(minDate);
console.log(maxDate);

2022-01-01T00:00:00.000Z
2022-03-15T00:00:00.000Z

In this example:

• The code finds the minimum and maximum dates in an array of Date objects using Math.min() and Math.max().
• Math.min(...dates): Finds the earliest date by spreading the dates array and comparing their timestamps.
• Math.max(...dates): Finds the latest date similarly.
• Converts the timestamps back to Date objects with new Date().

4. Using Array.prototype.sort with a custom comparator

Using Array.prototype.sort() with a custom comparator allows you to sort an array based on specific criteria by defining a comparison function.

let dates = [
    new Date("2024-05-15"),
    new Date("2024-05-17"),
    new Date("2024-05-13"),
    new Date("2024-05-20"),
];

dates.sort((a, b) => a - b);
let minDate = dates[0];
let maxDate = dates[dates.length - 1];

console.log("Min date:", minDate.toDateString());
console.log("Max date:", maxDate.toDateString());

Min date: Mon May 13 2024
Max date: Mon May 20 2024

In this example

• dates[0]: Gives the earliest (minimum) date.
• dates[dates.length - 1]: Gives the latest (maximum) date.
• The results are printed in a human-readable format using toDateString().