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Description

Converts a datetime value to an Excel serial date number (1900 date system). The integer part is the number of days since 1899-12-30; the fractional part is the time of day. This is the inverse of ExcelSerialToDate. Use it when writing data to a destination — typically a spreadsheet — that stores dates as numeric serial values.

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Syntax

DateToExcelSerial(datetime_value)

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Arguments

  • datetime_value - datetime expression to convert.

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Examples

  • DateToExcelSerial(ToDate('2020-01-01T00:00:00Z')) returns 43831.0
  • DateToExcelSerial(ToDate('2020-01-01T12:00:00Z')) returns 43831.5

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Return value datatype

double

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Impact of null value

If datetime_value is null, returns null.
  • ExcelSerialToDate — the inverse conversion.
  • ToDate — parse datetime values from strings or Unix milliseconds.
Last modified on October 5, 2026