A Journey through JavaScript Date Functions: Everything You Need to Know

Introduction:

Working with dates is a common task in JavaScript programming. JavaScript provides a rich set of built-in Date functions that allow developers to manipulate and format dates with ease. In this comprehensive guide, we will explore various Date functions in JavaScript, providing detailed explanations and examples for each function. By the end, you'll have a solid understanding of how to work with dates effectively in JavaScript.

List of JavaScript Date Functions:

1. Date()
2. new Date()
3. getDate()
4. getDay()
5. getFullYear()
6. getHours()
7. getMilliseconds()
8. getMinutes()
9. getMonth()
10. getSeconds()
11. getTime()
12. getTimezoneOffset()
13. getUTCDate()
14. getUTCDay()
15. getUTCFullYear()
16. getUTCHours()
17. getUTCMilliseconds()
18. getUTCMinutes()
19. getUTCMonth()
20. getUTCSeconds()
21. setDate()
22. setFullYear()
23. setHours()
24. setMilliseconds()
25. setMinutes()
26. setMonth()
27. setSeconds()
28. setTime()
29. setUTCDate()
30. setUTCFullYear()
31. setUTCHours()
32. setUTCMilliseconds()
33. setUTCMinutes()
34. setUTCMonth()
35. setUTCSeconds()
36. toDateString()
37. toISOString()
38. toJSON()
39. toLocaleDateString()
40. toLocaleString()
41. toLocaleTimeString()
42. toString()
43. toTimeString()
44. toUTCString()
45. UTC()

Now, let's delve into each function, providing a detailed explanation and example for better understanding.

1. Date():
The Date() function is used to create a new Date object representing the current date and time. Here's an example:

const currentDate = Date();
console.log(currentDate);

Output:

Tue Jun 29 2023 12:30:00 GMT+0530 (India Standard Time)

Explanation:
The Date() function, when called without any arguments, returns a string representing the current date and time. The output format varies based on the browser's implementation.

2. new Date():
The new Date() constructor creates a new Date object based on the provided arguments. Here's an example:

const specificDate = new Date('2023-06-29');
console.log(specificDate);

Output:

Tue Jun 29 2023 00:00:00 GMT+0530 (India Standard Time)

Explanation:
By passing a specific date string as an argument to new Date(), we can create a Date object representing that particular date. The output displays the date and time in the local time zone.

3. getDate():
The getDate() method returns the day of the month (from 1 to 31) for the specified Date object. Here's an example:

const date = new Date();
const dayOfMonth = date.getDate();
console.log(dayOfMonth);

Output:

29

Explanation:
The getDate() method retrieves the day of the month from the current Date object. In this example, it returns the value "29" since the current date is the 29th.

4. getDay():
The getDay() method returns the day of the week (from 0 to 6) for the specified Date object. Here's an example:

const date = new Date();
const dayOfWeek = date.getDay();
console.log(dayOfWeek);

Output:

2

Explanation:
The getDay() method retrieves the day of the week from the current Date object. It returns a value from 0 to 6, where 0 represents Sunday, 1 represents Monday, and so on. In this example, the output is "2" since Tuesday is the second day of the week.

5. getFullYear():
The getFullYear() method returns the four-digit year for the specified Date object. Here's an example:

const date = new Date();
const year = date.getFullYear();
console.log(year);

Output:

2023

Explanation:
The getFullYear() method retrieves the four-digit year from the current Date object. In this example, it returns the current year, which is "2023".

6. getHours():
The getHours() method returns the hour (from 0 to 23) for the specified Date object. Here's an example:

const date = new Date();
const hours = date.getHours();
console.log(hours);

Output:

12

Explanation:
The getHours() method retrieves the hour from the current Date object in 24-hour format. In this example, it returns the current hour, which is "12" (12 PM).

7. getMilliseconds():
The getMilliseconds() method returns the milliseconds (from 0 to 999) for the specified Date object. Here's an example:

const date = new Date();
const milliseconds = date.getMilliseconds();
console.log(milliseconds);

Output:

500

Explanation:
The getMilliseconds() method retrieves the milliseconds from the current Date object. In this example, it returns "500".

8. getMinutes():
The getMinutes() method returns the minutes (from 0 to 59) for the specified Date object. Here's an example:

const date = new Date();
const minutes = date.getMinutes();
console.log(minutes);

Output:

30

Explanation:
The getMinutes() method retrieves the minutes from the current Date object. In this example, it returns the current minutes, which is "30".

9. getMonth():
The getMonth() method returns the month (from 0 to 11) for the specified Date object. Here's an example:

const date = new Date();
const month = date.getMonth();
console.log(month);

Output:

5

Explanation:
The getMonth() method retrieves the month from the current Date object. It returns a value from 0 to 11, where 0 represents January, 1 represents February, and so on. In this example, the output is "5" since June is the sixth month.

10. getSeconds():
The getSeconds() method returns the seconds (from 0 to 59) for the specified Date object. Here's an example:

const date = new Date();
const seconds = date.getSeconds();
console.log(seconds);

Output:

0

Explanation:
The getSeconds() method retrieves the seconds from the current Date object. In this example, it returns the current seconds, which is "0".

11. getTime():
The getTime() method returns the numeric value corresponding to the time for the specified Date object. Here's an example:

const date = new Date();
const time = date.getTime();
console.log(time);

Output:

1677725888111

Explanation:
The getTime() method retrieves the time in milliseconds from the Unix epoch (January 1, 1970, 00:00:00 UTC) to

the current Date object. In this example, it returns the current time in milliseconds.

12. getTimezoneOffset():
The getTimezoneOffset() method returns the time zone offset in minutes for the current locale. Here's an example:

const date = new Date();
const timezoneOffset = date.getTimezoneOffset();
console.log(timezoneOffset);

Output:

-330

Explanation:
The getTimezoneOffset() method retrieves the time zone offset in minutes for the current locale. It returns a positive value if the local time zone is behind UTC and a negative value if it is ahead. In this example, the output is "-330" since the local time zone is UTC+05:30.

13. getUTCDate():
The getUTCDate() method returns the day of the month (from 1 to 31) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
const utcDayOfMonth = date.getUTCDate();
console.log(utcDayOfMonth);

Output:

29

Explanation:
The getUTCDate() method retrieves the day of the month from the current Date object, according to universal time (UTC). In this example, it returns the value "29" since the current date in UTC is the 29th.

14. getUTCDay():
The getUTCDay() method returns the day of the week (from 0 to 6) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
const utcDayOfWeek = date.getUTCDay();
console.log(utcDayOfWeek);

Output:

2

Explanation:
The getUTCDay() method retrieves the day of the week from the current Date object, according to universal time (UTC). It returns a value from 0 to 6, where 0 represents Sunday, 1 represents Monday, and so on. In this example, the output is "2" since Tuesday is the second day of the week in UTC.

15. getUTCFullYear():
The getUTCFullYear() method returns the four-digit year for the specified Date object, according to universal time. Here's an example:

const date = new Date();
const utcYear = date.getUTCFullYear();
console.log(utcYear);

Output:

2023

Explanation:
The getUTCFullYear() method retrieves the four-digit year from the current Date object, according to universal time (UTC). In this example, it returns the current year, which is "2023".

16. getUTCHours():
The getUTCHours() method returns the hour (from 0 to 23) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
const utcHours = date.getUTCHours();
console.log(utcHours);

Output:

7

Explanation:
The getUTCHours() method retrieves the hour from the current Date object, according to universal time (UTC), in 24-hour format. In this example, it returns the current hour, which is "7" (7 AM) in UTC.

17. getUTCMilliseconds():
The getUTCMilliseconds() method returns the milliseconds (from 0 to 999) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
const utcMilliseconds = date.getUTCMilliseconds();
console.log(utcMilliseconds);

Output:

500

Explanation:
The getUTCMilliseconds() method retrieves the milliseconds from the current Date object, according to universal time (UTC). In this example, it returns "500".

18. getUTCMinutes():
The getUTCMinutes() method returns the minutes (from 0 to 59) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
const utcMinutes = date.getUTCMinutes();
console.log(utcMinutes);

Output:

0

Explanation:
The getUTCMinutes() method retrieves the minutes from the current Date object, according to universal time (UTC). In this example, it returns the current minutes, which is "0" in UTC.

19. getUTCMonth():
The getUTCMonth() method returns the month (from 0 to 11) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
const utcMonth = date.getUTCMonth();
console.log(utcMonth);

Output:

5

Explanation:
The getUTCMonth() method retrieves the month from the current Date object, according to universal time (UTC). It returns a value from 0 to 11, where 0 represents January, 1 represents February, and so on. In this example, the output is "5" since June is the sixth month in UTC.

20. getUTCSeconds():
The getUTCSeconds() method returns the seconds (from 0 to 59) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
const utcSeconds = date.getUTCSeconds();
console.log(utcSeconds);

Output:

0

Explanation:
The getUTCSeconds() method retrieves the seconds from the current Date object, according to universal time (UTC). In this example, it returns the current seconds, which is "0" in UTC.

21. setDate():
The setDate() method sets the day of the month (from 1 to 31) for the specified Date object. Here's an example:

const date = new Date();
date.setDate(15);
console.log(date);

Output:

Thu Jun 15 2023 12:30:00 GMT+0530 (India Standard Time)

Explanation:
The setDate() method sets the day of the month for the current Date object. In this example, it sets the day to the 15th, resulting in a new Date object with the updated day.

22. setFullYear():
The setFullYear() method sets the four-digit year for the specified Date object. Here's an example:

const date = new Date();
date.setFullYear(2022);
console.log(date);

Output:

Thu Jun 29 2022 12:30:00 GMT+0530 (India Standard Time)

Explanation:
The setFullYear() method sets the year for the current Date object. In this example, it sets the year to 2022, resulting in a new Date object with the updated year.

23. setHours():
The setHours() method sets the hour (from 0 to 23) for the specified Date object. Here's an example:

const date = new Date();
date.setHours(18);
console.log(date);

Output:

Tue Jun 29 2023 18:30:00 GMT+0530 (India Standard Time)

Explanation:
The setHours() method sets the hour

for the current Date object. In this example, it sets the hour to 18 (6 PM), resulting in a new Date object with the updated hour.

24. setMilliseconds():
The setMilliseconds() method sets the milliseconds (from 0 to 999) for the specified Date object. Here's an example:

const date = new Date();
date.setMilliseconds(500);
console.log(date);

Output:

Tue Jun 29 2023 12:30:00 GMT+0530 (India Standard Time)

Explanation:
The setMilliseconds() method sets the milliseconds for the current Date object. In this example, it sets the milliseconds to 500, resulting in a new Date object with the updated milliseconds.

25. setMinutes():
The setMinutes() method sets the minutes (from 0 to 59) for the specified Date object. Here's an example:

const date = new Date();
date.setMinutes(45);
console.log(date);

Output:

Tue Jun 29 2023 12:45:00 GMT+0530 (India Standard Time)

Explanation:
The setMinutes() method sets the minutes for the current Date object. In this example, it sets the minutes to 45, resulting in a new Date object with the updated minutes.

26. setMonth():
The setMonth() method sets the month (from 0 to 11) for the specified Date object. Here's an example:

const date = new Date();
date.setMonth(8);
console.log(date);

Output:

Sun Sep 29 2023 12:30:00 GMT+0530 (India Standard Time)

Explanation:
The setMonth() method sets the month for the current Date object. In this example, it sets the month to September (8th month), resulting in a new Date object with the updated month.

27. setSeconds():
The setSeconds() method sets the seconds (from 0 to 59) for the specified Date object. Here's an example:

const date = new Date();
date.setSeconds(15);
console.log(date);

Output:

Tue Jun 29 2023 12:30:15 GMT+0530 (India Standard Time)

Explanation:
The setSeconds() method sets the seconds for the current Date object. In this example, it sets the seconds to 15, resulting in a new Date object with the updated seconds.

28. setTime():
The setTime() method sets the numeric value corresponding to the time for the specified Date object. Here's an example:

const date = new Date();
date.setTime(1625040000000);
console.log(date);

Output:

Thu Jun 29 2021 00:00:00 GMT+0530 (India Standard Time)

Explanation:
The setTime() method sets the time in milliseconds for the current Date object. In this example, it sets the time to the Unix timestamp value corresponding to June 30, 2021, resulting in a new Date object with the updated time.

29. setUTCDate():
The setUTCDate() method sets the day of the month (from 1 to 31) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
date.setUTCDate(15);
console.log(date);

Output:

Thu Jun 15 2023 12:30:00 GMT+0530 (India Standard Time)

Explanation:
The `setUTC

Date()` method sets the day of the month for the current Date object, according to universal time (UTC). In this example, it sets the day to the 15th, resulting in a new Date object with the updated day in UTC.

30. setUTCFullYear():
The setUTCFullYear() method sets the four-digit year for the specified Date object, according to universal time. Here's an example:

const date = new Date();
date.setUTCFullYear(2022);
console.log(date);

Output:

Thu Jun 29 2022 12:30:00 GMT+0530 (India Standard Time)

Explanation:
The setUTCFullYear() method sets the year for the current Date object, according to universal time (UTC). In this example, it sets the year to 2022, resulting in a new Date object with the updated year in UTC.

31. setUTCHours():
The setUTCHours() method sets the hour (from 0 to 23) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
date.setUTCHours(18);
console.log(date);

Output:

Tue Jun 29 2023 18:30:00 GMT+0530 (India Standard Time)

Explanation:
The setUTCHours() method sets the hour for the current Date object, according to universal time (UTC), in 24-hour format. In this example, it sets the hour to 18 (6 PM) in UTC, resulting in a new Date object with the updated hour.

32. setUTCMilliseconds():
The setUTCMilliseconds() method sets the milliseconds (from 0 to 999) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
date.setUTCMilliseconds(500);
console.log(date);

Output:

Tue Jun 29 2023 12:30:00 GMT+0530 (India Standard Time)

Explanation:
The setUTCMilliseconds() method sets the milliseconds for the current Date object, according to universal time (UTC). In this example, it sets the milliseconds to 500, resulting in a new Date object with the updated milliseconds in UTC.

33. setUTCMinutes():
The setUTCMinutes() method sets the minutes (from 0 to 59) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
date.setUTCMinutes(45);
console.log(date);

Output:

Tue Jun 29 2023 12:45:00 GMT+0530 (India Standard Time)

Explanation:
The setUTCMinutes() method sets the minutes for the current Date object, according to universal time (UTC). In this example, it sets the minutes to 45 in UTC, resulting in a new Date object with the updated minutes.

34. setUTCMonth():
The setUTCMonth() method sets the month (from 0 to 11) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
date.setUTCMonth(8);
console.log(date);

Output:

Sun Sep 29 2023 12:30:00 GMT+0530 (India Standard Time)

Explanation:
The setUTCMonth() method sets the month for the current Date object, according to universal time (UTC). In this example, it sets the month to September (8th month) in

UTC, resulting in a new Date object with the updated month.

35. setUTCSeconds():
The setUTCSeconds() method sets the seconds (from 0 to 59) for the specified Date object, according to universal time. Here's an example:

const date = new Date();
date.setUTCSeconds(15);
console.log(date);

Output:

Tue Jun 29 2023 12:30:15 GMT+0530 (India Standard Time)

Explanation:
The setUTCSeconds() method sets the seconds for the current Date object, according to universal time (UTC). In this example, it sets the seconds to 15 in UTC, resulting in a new Date object with the updated seconds.

36. toDateString():
The toDateString() method converts the date portion of a Date object into a human-readable string representation. Here's an example:

const date = new Date();
const dateString = date.toDateString();
console.log(dateString);

Output:

"Tue Jun 29 2023"

Explanation:
The toDateString() method converts the date portion of the Date object into a string representation in the format "Day Month Date Year". In this example, it returns a string representing the date.

37. toISOString():
The toISOString() method returns a string representation of the Date object in ISO 8601 format. Here's an example:

const date = new Date();
const isoString = date.toISOString();
console.log(isoString);

Output:

"2023-06-29T07:00:00.000Z"

Explanation:
The toISOString() method converts the Date object into a string representation in the ISO 8601 format. The returned string represents the date, time, and timezone offset. In this example, it returns the ISO string representation of the current date.

38. toJSON():
The toJSON() method returns a string representation of the Date object in JSON format. Here's an example:

const date = new Date();
const jsonString = date.toJSON();
console.log(jsonString);

Output:

"2023-06-29T12:30:00.000Z"

Explanation:
The toJSON() method converts the Date object into a string representation in JSON format. The returned string represents the date, time, and timezone offset in ISO 8601 format. In this example, it returns the JSON string representation of the current date.

39. toLocaleDateString():
The toLocaleDateString() method converts the date portion of the Date object into a human-readable string representation based on the current locale. Here's an example:

const date = new Date();
const localeDateString = date.toLocaleDateString();
console.log(localeDateString);

Output:

"6/29/2023"

Explanation:
The toLocaleDateString() method converts the date portion of the Date object into a string representation based on the current locale's formatting conventions. The specific format may vary based on the user's locale. In this example, it returns a localized string representing the date.

40. toLocaleString():
The toLocaleString() method converts the Date object into a human-readable string representation based on the current locale. Here's an example:

const date = new Date();
const localeString = date.toLocaleString();
console.log(localeString);

Output:

"6/29/2023, 12:30:00 PM"

Explanation:
The toLocaleString() method converts the Date object into a string representation based on the current locale's formatting conventions. The specific format may vary based on the user's locale. In this example, it returns a localized string representing the date and time.

41. toLocaleTimeString():
The toLocaleTimeString() method converts the time portion of the Date object into a human-readable string representation based on the current locale. Here's an example:

const date = new Date();
const localeTimeString = date.toLocaleTimeString();
console.log(localeTimeString);

Output:

"12:30:00 PM"

Explanation:
The toLocaleTimeString() method converts the time portion of the Date object into a string representation based on the current locale's formatting conventions. The specific format

may vary based on the user's locale. In this example, it returns a localized string representing the time.

42. toString():
The toString() method converts the Date object into a string representation. Here's an example:

const date = new Date();
const string = date.toString();
console.log(string);

Output:

"Tue Jun 29 2023 12:30:00 GMT+0530 (India Standard Time)"

Explanation:
The toString() method converts the Date object into a string representation using a default format. In this example, it returns a string representing the date, time, and timezone offset.

43. toTimeString():
The toTimeString() method converts the time portion of the Date object into a string representation. Here's an example:

const date = new Date();
const timeString = date.toTimeString();
console.log(timeString);

Output:

"12:30:00 GMT+0530 (India Standard Time)"

Explanation:
The toTimeString() method converts the time portion of the Date object into a string representation. In this example, it returns a string representing the time and timezone offset.

44. toUTCString():
The toUTCString() method converts the Date object into a string representation in UTC format. Here's an example:

const date = new Date();
const utcString = date.toUTCString();
console.log(utcString);

Output:

"Tue, 29 Jun 2023 07:00:00 GMT"

Explanation:
The toUTCString() method converts the Date object into a string representation in UTC format. In this example, it returns a string representing the date, time, and UTC timezone.

45. valueOf():
The valueOf() method returns the numeric value corresponding to the time for the specified Date object. Here's an example:

const date = new Date();
const value = date.valueOf();
console.log(value);

Output:

1687349400000

Explanation:
The valueOf() method returns the time value of the Date object as the number of milliseconds since January 1, 1970, 00:00:00 UTC. In this example, it returns the numeric value representing the current date and time in milliseconds.

These are some of the commonly used date functions in JavaScript. They allow you to manipulate, format, and convert date objects based on your requirements. Understanding and utilizing these functions will help you work effectively with dates and times in JavaScript.

Comments

[Tracy Gilmore]

I question if this article offers anything beyond that provided by the authoritative documentation at MDN?