Formualizer Docs
ReferenceFunctionsDate & Time Functions

DAY

Extracts the day-of-month (`1` to `31`) from a date serial.

Summary

Extracts the day-of-month (1 to 31) from a date serial.

Remarks

  • Fractional time is ignored; only the integer serial portion is used.
  • Serials are interpreted with Excel 1900 date semantics.
  • Output is the day within the month, not day-of-year.

Examples

Extract day from first-of-month
Grid
CellValue
No inputs on Sheet1.
Formula
=
Result
Not evaluated yet.
Expected
1
Extract day from leap date
Grid
CellValue
No inputs on Sheet1.
Formula
=
Result
Not evaluated yet.
Expected
29

FAQ

Does DAY return day-of-year or day-of-month?

DAY returns the day number within the month (1-31), not the ordinal day of the year.

Runtime metadata

Category

Date & Time

Signature

DAY(arg1: Number)

Arity

min 1, max 1

Arguments

arg1

Number · Scalar · coercion NumberLenientText

Caps

PURE

Source

crates/formualizer-eval/src/builtins/datetime/date_parts.rs

DATEVALUE

DATEVALUE: Parses a date string and returns its date serial number.

DAYS

Returns the number of whole days between two date serial values.

On this page

SummaryRemarksExamplesRelated functionsFAQDoes DAY return day-of-year or day-of-month?Runtime metadata