"use strict";
/*
* Date Utility Functions
* ----------------------
* This file demonstrates:
* 1. Creating Date objects
* 2. Retrieving date components
* 3. Formatting dates
* 4. Performing date calculations
* 5. Using a custom helper function
*/
/*
* Key Date Methods
* ----------------
* const date = new Date();
*
* date.getFullYear(); // Year
* date.getMonth(); // Month (0-11)
* date.getDate(); // Day of month
* date.getDay(); // Day of week (0-6)
*
* date.getHours();
* date.getMinutes();
* date.getSeconds();
*
* date.setDate(15);
* date.setMonth(11);
*
* date.toISOString();
* date.toLocaleDateString();
* date.toLocaleString();
*/
/**
* Formats a Date object as YYYY-MM-DD HH:mm:ss
*
* @param {Date} date - The Date object to format.
* @returns {string} Formatted date string.
*/
function formatDate(date) {
if (!(date instanceof Date) || Number.isNaN(date.getTime())) {
throw new Error("Invalid Date object.");
}
const year = date.getFullYear();
const month = String(date.getMonth() + 1).padStart(2, "0");
const day = String(date.getDate()).padStart(2, "0");
const hours = String(date.getHours()).padStart(2, "0");
const minutes = String(date.getMinutes()).padStart(2, "0");
const seconds = String(date.getSeconds()).padStart(2, "0");
return `${year}-${month}-${day} ${hours}:${minutes}:${seconds}`;
}
/**
* Adds a specified number of days to a date.
*
* @param {Date} date - Original date.
* @param {number} days - Number of days to add.
* @returns {Date} New Date object.
*/
function addDays(date, days) {
if (!(date instanceof Date) || Number.isNaN(date.getTime())) {
throw new Error("Invalid Date object.");
}
const result = new Date(date);
result.setDate(result.getDate() + days);
return result;
}
// ----------------------------------------------------
// Usage Examples
// ----------------------------------------------------
// 1. Current date and time
const now = new Date();
console.log("Current Date Object:");
console.log(now);
// 2. Formatted current date
console.log("\nFormatted Current Date:");
console.log(formatDate(now));
// 3. Specific date
const birthday = new Date("1995-07-15T10:30:00");
console.log("\nSpecific Date:");
console.log(formatDate(birthday));
// 4. Accessing date parts
console.log("\nDate Components:");
console.log("Year:", birthday.getFullYear());
console.log("Month:", birthday.getMonth() + 1); // Months are 0-based
console.log("Day:", birthday.getDate());
console.log("Hour:", birthday.getHours());
console.log("Minute:", birthday.getMinutes());
// 5. Adding days
const futureDate = addDays(now, 30);
console.log("\n30 Days From Now:");
console.log(formatDate(futureDate));
// 6. Date difference in days
const diffMs = futureDate - now;
const diffDays = diffMs / (1000 * 60 * 60 * 24);
console.log("\nDifference:");
console.log(`${diffDays} days`);
// 7. ISO format (recommended for APIs)
console.log("\nISO Format:");
console.log(now.toISOString());
// 8. Locale-based formatting
console.log("\nLocalized Format:");
console.log(
now.toLocaleString("en-US", {
dateStyle: "full",
timeStyle: "long"
})
);
/*
run:
Current Date Object:
2026-10-16T15:10:51.402Z
Formatted Current Date:
2026-10-16 15:10:51
Specific Date:
1995-07-15 10:30:00
Date Components:
Year: 1995
Month: 7
Day: 15
Hour: 10
Minute: 30
30 Days From Now:
2026-11-15 15:10:51
Difference:
30 days
ISO Format:
2026-10-16T15:10:51.402Z
Localized Format:
Friday, October 16, 2026 at 3:10:51 PM UTC
*/
