DAY Formula in Excel

Returns the day portion of a date or duration.

Syntax

Formula structure

Source: Quadratic docs
=DAY(date)
date
Required: Yes

Required argument used by the DAY formula.

Examples for the day formula in excel

Copy these examples into a spreadsheet and adjust the ranges for your own data.

DAY syntax pattern

=DAY(date)

Use this DAY pattern as the starting point for your spreadsheet formula.

DAY in a worksheet

=DAY(date)

Returns the day portion of a date or duration.

When to use DAY

Use DAY when you need to return the day portion of a date or duration.

  • Construct dates, times, and durations.
  • Extract time parts and shift dates for reporting.

How DAY works in Quadratic

In Quadratic, DAY follows the syntax DAY(date). The function works inside Quadratic formulas and can be combined with spreadsheet ranges, tables, and other formulas.

Common DAY mistakes

Most DAY issues come from mismatched argument types, ranges that do not cover the intended data, or optional parameters being omitted when the default behavior is not what you expected.

  • Check each required parameter before copying the formula across a sheet.
  • Confirm that ranges line up with the rows or columns you intend to analyze.
  • Use Quadratic AI to explain or debug the formula when the result looks wrong.

Related formulas

DAY formula FAQ

What does the day formula in excel do?

DAY returns the day portion of a date or duration.

What is the syntax for DAY?

The syntax is DAY(date). Required and optional parameters are listed at the top of this guide.

Can Quadratic AI help with DAY?

Yes. Quadratic AI can write a DAY formula, explain existing formula logic, or help debug broken references and unexpected results.

Quadratic AI

Struggling with formulas? Use Quadratic AI.

Spreadsheet formulas are powerful, but they get painful fast. A DAY formula can start simple, then turn into logic that is hard to understand, easy to break, and difficult to share with the rest of your team.

Quadratic AI helps you write formulas, explain formula logic, debug broken references, and move beyond formulas when advanced analysis needs Python, SQL, charts, or connected data.

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Why formulas slow teams down

  • Long formulas become hard to read, understand, and trust.
  • Formula logic breaks when rows, columns, or assumptions change.
  • Manual updates make dashboards and reports fragile over time.
  • Complex formulas are difficult to explain, review, and share with teammates.
  • Advanced analysis quickly outgrows formula-only workflows.