Spreadsheet Practice

How to get the first day of the month in Excel

Formula (Excel and Google Sheets)

=EOMONTH(B2,-1)+1

Use =EOMONTH(B2,-1)+1: the day after the end of last month is the first of this month.

Result on the example
one result per row in C2, filled down to C6
Works in
Every current version
Google Sheets
Same formula

See it work

The formula is already in C2, filled down to C6. Change any input and the result updates, or edit the formula to experiment.

How it works

EOMONTH(B2,-1) is the last day of the previous month, so one day later is the first of this month. The result is a real date, which makes it a good month key for SUMIFS, pivot tables and charts.

=EOMONTH(B2,-1)+1

Result46023

  1. B21/19/2026

    The value in B2.

  2. -1-1

    Makes the value negative.

  3. EOMONTH(B2,-1)12/31/2025 (46022)

    EOMONTH: Last day of the month, months away.

    • start_dateB21/19/2026
    • months-1-1
  4. EOMONTH(B2,-1)+146023

    The + operator adds.

In Google Sheets

The same formula works in Google Sheets: =EOMONTH(B2,-1)+1. We ran it in Google Sheets mode on the same data and it returns the same results.

Other ways to do it

Each one was run on the same example sheet.

FormulaResultWhen to use it
=DATE(YEAR(B2),MONTH(B2),1)1/1/2026, 2/1/2026, 2/1/2026…Builds the date from the year and month with day 1.
=B2-DAY(B2)+11/1/2026, 2/1/2026, 2/1/2026…Steps back by the day number. Short, but keeps any time in B2.

Common mistakes

  • TEXT(B2,"mmm yyyy") looks similar but returns text, which sorts alphabetically. Keep the date and give it a "mmm yyyy" number format.
  • If B2 has a time, EOMONTH drops it, so the result is midnight on the 1st.

Try it yourself

Same data, empty answer cell. Your formula is graded instantly, then re-checked on changed data, so a typed-in number won't pass.

Get the first day of the month

In C2, return the first day of the month of each transaction date, and fill down to C6.

Questions

How do I get the first day of next month?

=EOMONTH(B2,0)+1.

How do I get the first day of the current month?

Use today's date: =EOMONTH(TODAY(),-1)+1.

Checked by running on 2026-10-30: every formula and result on this page was calculated by the Spreadsheet Practice formula engine, in both Excel and Google Sheets modes.