Date and Time

Date and Time in JavaScript

JavaScript provides the Date object to work with dates and times. You can create, modify, and format dates using built-in methods.

Creating a Date Object

There are multiple ways to create a date in JavaScript:

Current Date and Time

let now = new Date();
console.log(now); 
// Output: Current date and time (e.g., 2025-03-11T12:34:56.789Z)

Specific Date and Time (YYYY, MM, DD, HH, MM, SS, MS)

let specificDate = new Date(2025, 2, 11, 14, 30, 0); // Month starts from 0 (0 = January)
console.log(specificDate); // Output: Tue Mar 11 2025 14:30:00

Date from a String

let fromString = new Date("2025-03-11T14:30:00");
console.log(fromString); // Output: Tue Mar 11 2025 14:30:00

Date from a Timestamp (Milliseconds since Jan 1, 1970)

let timestampDate = new Date(1710151800000);
console.log(timestampDate);

Getting Date Components

You can extract parts of a date using the get methods.

let date = new Date();

console.log(date.getFullYear());  // 🟢 Year (e.g., 2025)
console.log(date.getMonth());     // 🟢 Month (0-11, where 0 = January)
console.log(date.getDate());      // 🟢 Day of the month (1-31)
console.log(date.getDay());       // 🟢 Day of the week (0-6, where 0 = Sunday)
console.log(date.getHours());     // 🟢 Hours (0-23)
console.log(date.getMinutes());   // 🟢 Minutes (0-59)
console.log(date.getSeconds());   // 🟢 Seconds (0-59)
console.log(date.getMilliseconds()); // 🟢 Milliseconds (0-999)
console.log(date.getTime());      // 🟢 Timestamp (milliseconds since 1970)

Setting Date Components

You can modify a date using set methods.

let date = new Date();

date.setFullYear(2026); // Change year to 2026
date.setMonth(5);       // Change month to June (5 = June)
date.setDate(20);       // Change day to 20
date.setHours(10);      // Change hour to 10 AM

console.log(date); 

Formatting Dates

JavaScript provides methods to convert dates into strings.

Convert to Date String

console.log(date.toDateString()); // Output: Tue Jun 20 2026
console.log(date.toISOString());  // Output: 2026-06-20T10:00:00.000Z
console.log(date.toUTCString());  // Output: Sat, 20 Jun 2026 10:00:00 GMT
console.log(date.toLocaleString()); // Output: 6/20/2026, 10:00:00 AM (format depends on locale)
console.log(date.toLocaleDateString()); // Output: 6/20/2026
console.log(date.toLocaleTimeString()); // Output: 10:00:00 AM

Comparing Dates

let date1 = new Date(2025, 2, 11);
let date2 = new Date(2026, 5, 20);

console.log(date1 > date2); // false
console.log(date1 < date2); // true
console.log(date1.getTime() === date2.getTime()); // false

Working with Timestamps

let now = Date.now(); // Current timestamp in milliseconds
console.log(now);

let fiveDaysLater = now + 5 * 24 * 60 * 60 * 1000; // Add 5 days
console.log(new Date(fiveDaysLater));

Date Manipulation with Intl.DateTimeFormat

let formatter = new Intl.DateTimeFormat("en-US", { weekday: "long", year: "numeric", month: "long", day: "numeric" });
console.log(formatter.format(new Date())); 
// Output: "Tuesday, March 11, 2025"

🎯 Summary

✔ Create dates with new Date(), timestamps, or strings.
✔ Get parts of a date using getFullYear(), getMonth(), getDate(), etc.
✔ Modify dates with setFullYear(), setMonth(), setDate(), etc.
✔ Format dates with toLocaleString(), toDateString(), etc.
✔ Compare dates using getTime().

🚀 JavaScript provides powerful tools to work with dates and times! Let me know if you need more examples. 😊