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EOMONTH Function (LibreOffice Calc)

Date & Time Beginner LibreOffice Calc LibreOffice 3.0

The EOMONTH function returns the last day of the month that is a specified number of months before or after a given date. It is essential for financial schedules, billing cycles, and month-end calculations.

The **EOMONTH** function returns the **last day of the month** that is a specified number of months before or after a given date. It is the most reliable way to compute month-end boundaries, making it indispensable for financial modeling, billing cycles, forecasting, and any workflow that depends on month-end logic.

What the EOMONTH Function Does

  • Returns the last day of a target month
  • Adds or subtracts whole months
  • Handles leap years and variable month lengths
  • Works with serial dates or text dates
  • Returns a serial date number formatted as a date

It is designed to be precise, predictable, and ideal for month-end calculations.

Syntax

EOMONTH(start_date; months)

Arguments

  • start_date:
    The reference date.

  • months:
    Number of months to offset (positive or negative).

Basic Examples

Last day of the current month

=EOMONTH("2024-01-15"; 0)

Returns 2024‑01‑31.

Last day of next month

=EOMONTH("2024-01-15"; 1)

Returns 2024‑02‑29 (leap year).

Last day of previous month

=EOMONTH("2024-03-10"; -1)

Returns 2024‑02‑29.

Using cell references

=EOMONTH(A1; B1)

Advanced Examples

First day of next month

=EOMONTH(A1; 0) + 1

First day of current month

=EOMONTH(A1; -1) + 1

Days in the current month

=EOMONTH(A1; 0) - EOMONTH(A1; -1)

Generate a month-end schedule

=EOMONTH($A$1; ROW(A1)-1)

Compute quarter-end

=EOMONTH(A1; MOD(3 - MONTH(A1); 3))

Compute fiscal year-end (March 31 example)

=EOMONTH(DATE(YEAR(A1)+(MONTH(A1)>3); 3; 1); 0)

Add months to a text date

=EOMONTH(DATEVALUE(A1); 6)

Add months to Excel serial dates imported as text

=EOMONTH(DATE(1899;12;30)+VALUE(A1); 1)

Compute the last day of the year

=EOMONTH(DATE(YEAR(A1);12;1); 0)

Compute the last day of the quarter

=EOMONTH(A1; 3 - MOD(MONTH(A1); 3))

Edge Cases and Behavior Details

EOMONTH returns a number, not text

Accepts:

  • Real dates
  • Serial numbers
  • DATEVALUE outputs
  • ISO date strings

Invalid text → Err:502

Time components are ignored

=EOMONTH("2024-01-15 23:59"; 0) → 2024‑01‑31

Negative months allowed

Large offsets allowed

=EOMONTH("2024-01-01"; 1200) → year 2124

Leap-year aware

EOMONTH of an error → error propagates

Common Errors and Fixes

Err:502 — Invalid argument

Cause:

  • Text not recognized as a date
  • Non-numeric month offset

Fix:

  • Wrap with DATEVALUE
  • Ensure months is numeric

Wrong result due to text dates

Fix:

  • Normalize with DATEVALUE

Unexpected month-end behavior

Cause:

  • Misunderstanding of month offset logic

Fix:

  • Use EDATE if you want same-day-of-month behavior

Best Practices

  • Use EOMONTH for all month-end calculations
  • Use EDATE for same-day-of-month offsets
  • Use DATEVALUE to normalize text dates
  • Use EOMONTH(A1;0)+1 for first-of-month logic
  • Use EOMONTH with ROW() or SEQUENCE() to generate schedules
EOMONTH is your month‑end anchor — perfect for financial modeling, billing cycles, forecasting, and any workflow that depends on precise month boundaries.
  • Use EDATE for same-day-of-month offsets
  • Use DATE for custom date construction
  • Use DATEDIF for interval calculations
  • Use DAYS for day differences
  • Use YEARFRAC for fractional-year differences

By mastering EOMONTH and its companion functions, you can build powerful, reliable, and fully dynamic month‑end workflows in LibreOffice Calc.

Reproducible example (tested in LibreOffice Calc)

This standalone example was calculated in LibreOffice Calc 25.2.3.2 and matched the expected value. It is a practical cross-check of one usage, not proof that every example elsewhere on this page is correct.

=DAY(EOMONTH(DATE(2025;2;1);0))

Expected result: 28.

Identify the last day of a non-leap February.

If the result differs, check the referenced cells, argument separators and number formatting. For more information, consult the LibreOffice Calc official help.