JavaScript Date getFullYear() Method

What You’ll Learn

getFullYear() returns the four-digit calendar year (e.g. 2026) from a Date object in local time. This guide covers syntax, five examples, UTC comparisons, validation, and common real-world patterns like copyright footers.

Introduction

Copyright notices, age displays, fiscal-year filters, and “posted in 2026” labels all need the year component from a Date. The getFullYear() method returns that value as a plain integer using the user’s local timezone.

Pair it with getMonth() and getDate() to build custom formats, or use getUTCFullYear() when your app standardizes on UTC.

Understanding the getFullYear() Method

Date.prototype.getFullYear() is a zero-argument instance method. It never mutates the original Date—it only reads the year component according to local time rules.

Unlike the deprecated getYear() (which returned year - 1900), getFullYear() always gives you the complete four-digit year, which is what humans expect in UI copy and logs.

📝 Syntax

dateObj.getFullYear()

Parameters

• None.

Return value

• Integer four-digit year (e.g. 2026) for a valid date in local time.
• NaN if dateObj is an invalid Date.

Examples Gallery

Open DevTools Console (F12) or use Try-it links. Fixed dates use new Date(year, monthIndex, day) to avoid string parsing surprises.

const currentDate = new Date();
const currentYear = currentDate.getFullYear();

console.log("Current year:", currentYear);

Current year: 2026

const july4 = new Date(2026, 6, 4);

console.log(july4.getFullYear());  // 2026
console.log(july4.getMonth());     // 6 (July)
console.log(july4.getDate());      // 4

2026
6
4

function safeGetFullYear(date) {
  if (!(date instanceof Date) || Number.isNaN(date.getTime())) {
    return null;
  }
  return date.getFullYear();
}

console.log(safeGetFullYear(new Date()));              // e.g. 2026
console.log(safeGetFullYear(new Date("not-a-date")));  // null

2026
null

// HTML: <footer>© <span id="copyrightYear"></span> CodeToFun</footer>

const yearEl = document.getElementById("copyrightYear");
if (yearEl) {
  yearEl.textContent = new Date().getFullYear();
}

© 2026 CodeToFun

function calculateAge(birthDate) {
  const today = new Date();
  let age = today.getFullYear() - birthDate.getFullYear();

  const birthdayPassed =
    today.getMonth() > birthDate.getMonth() ||
    (today.getMonth() === birthDate.getMonth() &&
      today.getDate() >= birthDate.getDate());

  if (!birthdayPassed) {
    age -= 1;
  }
  return age;
}

const birthDate = new Date(1990, 4, 15); // May 15, 1990
console.log("Age:", calculateAge(birthDate), "years");

Age: 36 years

🚀 Common Use Cases

• Copyright footers — auto-update the year in site footers.
• Age gates — compare birth year against a minimum age rule.
• Year filters — “show posts from 2025” in dashboards.
• Invoice headers — fiscal year labels on PDFs.
• Form defaults — pre-select year in date pickers.
• Analytics buckets — group events by calendar year.

📝 Notes

• getFullYear() is local; use getUTCFullYear() when you standardize on UTC.
• Never use deprecated getYear()—it returns year - 1900.
• Invalid dates propagate NaN—validate first.
• Near midnight on Dec 31 / Jan 1, local year can differ from UTC year on the same instant.
• Age from year subtraction alone is approximate; include month and day for accuracy.
• Store the year in a variable if you use it multiple times in the same function for readability.

💡 Best Practices