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Interactive lesson · Excel & Google Sheets

The Excel MONTH function, explained interactively.

Last updated: April 2026

MONTH extracts the month component from a date, returning an integer between 1 (January) and 12 (December). It’s the counterpart to DATE’s second argument — where DATE takes a month integer to build a date, MONTH pulls that integer back out. Pair it with YEAR and DAY to fully decompose any date.

01 · See it work

How to use MONTH

  1. Type =MONTH( and supply a date — a cell reference containing a date, a DATE() formula, or any formula that returns a real Excel date serial.
  2. Close the parenthesis. MONTH returns an integer from 1 to 12 — there are no extra arguments.
  3. The result is a plain integer, not a date. Format the output cell as General or Number — not as Date, which would misinterpret the integer as a serial number.
  4. To display the month as a name, wrap with CHOOSE(MONTH(A2), "Jan", ..., "Dec") or use TEXT(A2, "MMMM") directly on the original date cell.
FUNCTIONMONTH
Extracts the month number (1–12) from a date. January is 1, December is 12. Pair with CHOOSE() or TEXT(date, "MMMM") to render month names.
ARG 1serial_number
A real Excel date serial — a cell with a date, a DATE() formula, or any formula returning a serial. Time portions are ignored. Text dates require DATEVALUE() first.
B2
fx
=MONTH(DATE(2026, 4, 19))
AB
1DateSerial
22026-04-1946131
3
4MONTH result4
=MONTH(DATE(2026, 4, 19)) 4. That’s April 19, 2026 (Sunday) — result range 112.
02 · Syntax, argument by argument

MONTH syntax and arguments

One required argument — the date to extract from. See Microsoft’s official MONTH reference for the canonical specification.

=MONTH(serial_number)
serial_number
A real Excel date — a cell reference containing a date, a DATE() result, or any formula returning a date serial number. Text strings that look like dates (e.g. "2026-04-19") return #VALUE!; wrap with DATEVALUE to coerce text first. MONTH returns values 1–12 for any valid date.
03 · In the wild

MONTH examples

Four patterns covering the most common real-world MONTH use cases.

Example 1: Extract month number from dates

The direct use — pull the month integer from each date in a column. The result is always a number 1–12.

=MONTH(A2)

Drag down a column of dates to produce a month-number helper column. Use this as a key for SUMIFS or pivot tables to aggregate by month across all years.

Example 2: Convert month number to name with CHOOSE

MONTH returns 1–12, but reports often need “Jan”, “Feb”, etc. CHOOSE maps the number to a name.

=CHOOSE(MONTH(A2),"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec")

The CHOOSE list acts as a lookup table: position 1 returns “Jan”, position 12 returns “Dec”. Swap the short names for full names (“January”, etc.) as needed. The alternative TEXT(A2, "MMMM") is shorter but applies locale formatting.

Example 3: Group sales by month

Add a MONTH helper column to a sales table. Then use SUMIFS to total by month number.

=MONTH(A2)

Column D shows the month number for each sale. A downstream formula like =SUMIFS(B:B, D:D, 1) would sum January sales. Change A4 to a different month and D4 updates automatically.

Example 4: Flag dates in a specific month

Combine MONTH with IF to create a conditional label — useful for seasonal rules or year-end logic.

=IF(MONTH(A2)=12,"December","Other")

Change the 12 to any month number to test a different season. For multi-month checks use OR: =IF(OR(MONTH(A2)=11, MONTH(A2)=12), "Q4", "Other").

04 · Errata

Common MONTH errors and fixes

Three failure modes — each with what to check and how to recover.

MONTH returns #VALUE!

Cause: the argument is text, not a real date. This is the most common MONTH error — text cells that look like dates (left-aligned, from CSV imports or copy-paste) are not date serials.

Wrap with DATEVALUE(): =MONTH(DATEVALUE(A2)). Or replace the text with a DATE() formula. Check alignment: real dates right-align, text dates left-align.

MONTH returns a serial number instead of 1–12

Cause: the output cell is formatted as Date. MONTH returns a plain integer like 4, but a date format turns 4 into 1900-01-04.

Format the result cell as General or Number. MONTH’s output is an integer — never format it as a date.

MONTH shows wrong month due to locale date ambiguity

Cause: date strings like 04/05/2026 are interpreted as DD/MM or MM/DD depending on regional settings. MONTH may return 4 in one locale and 5 in another.

Use unambiguous date input: =DATE(2026, 4, 5) always means April 5, regardless of locale. Avoid raw date strings in formulas. Use ISO format YYYY-MM-DD when entering dates manually.

05 · Kindred functions

YEAR, MONTH & DAY compared

The three date-extraction functions are a family — they share the same single-argument syntax and always return integers.

FunctionReturnsRangeTypical use
YEARYear integer1900–9999Fiscal year grouping, age approximation, period anchors
MONTHMonth integer1–12Monthly grouping, CHOOSE for month names, seasonal flags
DAYDay-of-month integer1–31Month-end checks, days-remaining, payroll cut-off flags
DATEDate serialAny valid dateReconstruct a date from YEAR/MONTH/DAY components

Rule of thumb: YEAR, MONTH, and DAY decompose a date into integers; DATE assembles integers back into a date. A common pattern combining all four: =DATE(YEAR(A2), MONTH(A2), 1) — the first day of the same month and year as A2.

06 · Marginalia

MONTH frequently asked questions

6.01What does the MONTH function return in Excel?

MONTH returns an integer between 1 and 12 representing the month component of the date passed to it. January = 1, December = 12. It always returns a whole number — use CHOOSE or TEXT to convert the number to a month name if you need text output.

6.02How do I convert a month number to a month name in Excel?

Use CHOOSE: =CHOOSE(MONTH(A2),"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"). This maps 1→Jan, 2→Feb, through 12→Dec. For full names replace the short names. Alternatively, TEXT(A2, "MMMM") returns the full month name directly from the date, but requires the full date rather than just a MONTH number.

6.03Does MONTH work on text-stored dates?

No — MONTH requires a real Excel date serial number. Text like "2026-04-19" returns #VALUE!. Wrap with DATEVALUE to convert first: =MONTH(DATEVALUE(A2)). Or use Data → Text to Columns → Date format to convert the column in place. Real dates right-align in cells; text dates left-align.

6.04How do I sum sales for a specific month across all years?

Use SUMPRODUCT: =SUMPRODUCT((MONTH(A2:A100)=4)*B2:B100) sums all values in B where the date in A is April (month 4), across any year. If you also want to restrict by year, add another condition: =SUMPRODUCT((MONTH(A2:A100)=4)*(YEAR(A2:A100)=2026)*B2:B100).

6.05Why does MONTH return a different number than expected on some dates?

The most common cause is that the date is stored as text and Excel is interpreting it ambiguously (e.g. MM/DD vs DD/MM). Check if the cell left-aligns — that signals text, not a real date. Also check the regional date setting: in some locales, 04/05/2026 means May 4, in others it means April 5. Use explicit =DATE(2026, 4, 5) to avoid locale ambiguity.

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