JavaScript Date getUTCMonth() Method

What You’ll Learn

getUTCMonth() returns the zero-based month index (0–11) from a Date object in UTC. This guide covers syntax, the January = 0 rule, five examples, and comparisons with local getters.

Introduction

Global reporting often buckets data by UTC calendar months. The JavaScript Date object stores one instant internally; getUTCMonth() reads the month index according to UTC—not the user’s local timezone.

If you need the month for a user-facing local calendar, use getMonth(). Use getUTCMonth() when your logic follows UTC month boundaries.

Understanding the getUTCMonth() Method

Date.prototype.getUTCMonth() is a zero-argument instance method. It never mutates the original Date—it only reads the UTC month index as an integer from 0 (January) to 11 (December).

The zero-based index matches Date.UTC(year, monthIndex, day) and local getMonth(). March is always index 2, never 3.

📝 Syntax

dateObj.getUTCMonth()

Parameters

• None.

Return value

• Integer 0–11 for a valid date in UTC (0 = January).
• NaN if dateObj is an invalid Date.

Month index table

• 0 — January
• 1 — February
• 2 — March
• …
• 11 — December

Examples Gallery

Open DevTools Console (F12) or use Try-it links. Fixed UTC dates use Date.UTC so month indexes stay predictable.

const march15Utc = new Date(Date.UTC(2026, 2, 15));
const monthIndex = march15Utc.getUTCMonth();

console.log(monthIndex); // 2 (March)

2

const date = new Date(Date.UTC(2026, 1, 15));
const monthNumber = date.getUTCMonth() + 1;

console.log("Calendar month:", monthNumber); // 2 (February)

Calendar month: 2

const MONTHS = [
  "January", "February", "March", "April",
  "May", "June", "July", "August",
  "September", "October", "November", "December"
];

const date = new Date(Date.UTC(2026, 1, 15));
console.log("UTC month:", MONTHS[date.getUTCMonth()]);
// UTC month: February

UTC month: February

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

console.log(safeGetUTCMonth(new Date(Date.UTC(2026, 1, 15))));  // 1
console.log(safeGetUTCMonth(new Date("not-a-date")));              // null

1
null

// Jan 31, 2026 at 23:30 UTC
const date = new Date("2026-01-31T23:30:00.000Z");

console.log("UTC month:", date.getUTCMonth());   // 0 (January)
console.log("Local month:", date.getMonth());    // depends on timezone

UTC month: 0
Local month: 1

🚀 Common Use Cases

• UTC dashboards — bucket metrics by UTC calendar month.
• API date parts — assemble YYYY-MM-DD with UTC getters.
• Billing cycles — align invoices on UTC month boundaries.
• Log analysis — filter events by UTC month index.
• Test fixtures — assert month parts from Date.UTC.
• Same-month checks — pair with getUTCFullYear().

📝 Notes

• getUTCMonth() is zero-based: January = 0, December = 11.
• Use getUTCMonth() + 1 for human month numbers 1–12.
• Invalid dates propagate NaN—validate with Number.isNaN(date.getTime()).
• Compare months across years with getUTCFullYear(), not month alone.
• For full UTC strings, toISOString() is often simpler than manual getters.
• Use UTC getters together; do not mix with local getters in one label.

💡 Best Practices