Date Functions
Intermediate

The first day of the month with EOMONTH

The end of last month plus one day.

Task:

To group expenses by month, each date needs its month's first day. In B2:B6 give the first day of the month for each date.

Interactive Spreadsheet

Read about EOMONTH

Hints

+5 XPno-hints bonus

Solve it on your own to keep the bonus. Each hint gets one step closer to the formula.

Variations of EOMONTH

0/4

The same formula in the other shapes it takes at work.

  1. EOMONTH Function

    Find the last day of the month using EOMONTH.

    Core
    Intermediate
  2. The first day of the month with EOMONTH

    The end of last month plus one day.

    Intermediate
  3. Payment terms: end of the following month

    A positive offset moves forward by whole months.

    Intermediate
  4. How many days in the month?

    DAY of the month's last day is its length.

    Intermediate

The data in this exercise

This is the grid you start with. Cell references in the task — B6, C2 — point at the row numbers and column letters below.

6 rows × 2 columns5 cells you fill in
AB
1Expense dateMonth start
21/18/2024
32/29/2024
43/1/2024
512/31/2024
61/9/2025
What this exercise teachesMay contain the answer

Excel has no START-OF-MONTH function, and this is the idiom that stands in for it. Every date in a month maps to the same first day, which makes it a clean key for SUMIF, pivot tables or charts.