convert Excel Date Serial Number to Regular Date

Question

I got a column called DateOfBirth in my csv file with Excel Date Serial Number Date

Example:

  36464
  37104
  35412

When i formatted cells in excel these are converted as

  36464 => 1/11/1999
  37104 => 1/08/2001
  35412 => 13/12/1996

I need to do this transformation in SSIS or in SQL. How can this be achieved?

Answer 1

...old question, but here's what we use in SQL Server for moderate volumes (a scalar function) - if you need high performance, don't use a function (this can be encoded into a single line with some gymnastics) but for clarity and for less-than-1,000,000 row imports, etc., it's very evident.

You can also change the return type to other date-based types if needed.

CREATE FUNCTION dbo.FromExcelDateNum(
  -- Excel date number value
  @ExcelDateNum int
)
RETURNS DATETIME
AS
BEGIN
  RETURN CASE
    -- NULL -> NULL
    WHEN @ExcelDateNum IS NULL THEN NULL
    -- LESS THAN OR EQUAL TO 0 -> NULL
    WHEN @ExcelDateNum <= 0 THEN NULL
    -- Up to 1900-02-28
    WHEN @ExcelDateNum < 60 THEN DATEADD(DAY, @ExcelDateNum, '1899-12-31')
    -- Special case - a very old bug that Excel thinks
    -- 1900-02-29 is a real date but it's not:
    -- 1900 was not a leap year - leap years are all
    -- years divisible by 4 but not divisible by 100 unless
    -- also divisible by 1000, so:
    -- 2003 - no (not divisible by 4)
    -- 1984 - yes (divisible by 4)
    -- 1900 - no (divisible by 100 but not by 1000)
    -- 2000 - yes (divisible by 1000)
    WHEN @ExcelDateNum = 60 THEN NULL
    -- 1900-03-01 and later - offset from 1899-12-30 to compensate
    -- for Excel value being +1 too high due to including 1900-02-29
    ELSE DATEADD(DAY, @ExcelDateNum, '1899-12-30')
  END
END

Answer 2

You can cast it to a SQL SMALLDATETIME:

CAST(36464 - 2 as SMALLDATETIME)

MS SQL Server counts its dates from 01/01/1900 and Excel from 12/30/1899 = 2 days less.

Answer 3

tldr:

select cast(@Input - 2e as datetime)

Explanation:

Excel stores datetimes as a floating point number that represents elapsed time since the beginning of the 20th century, and SQL Server can readily cast between floats and datetimes in the same manner. The difference between Excel and SQL server's conversion of this number to datetimes is 2 days (as of 1900-03-01, that is). Using a literal of 2e for this difference informs SQL Server to implicitly convert other datatypes to floats for very input-friendly and simple queries:

select
    cast('43861.875433912' - 2e as datetime) as ExcelToSql, -- even varchar works!
    cast(cast('2020-01-31 21:00:37.490' as datetime) + 2e as float) as SqlToExcel

-- Results:
-- ExcelToSql                          SqlToExcel
-- 2020-01-31 21:00:37.490        43861.875433912

Answer 4

For those looking how to do this in excel (outside of formatting to a date field) you can do this by using the Text function https://exceljet.net/excel-functions/excel-text-function

i.e.

A1 = 132134
=Text(A1,"MM-DD-YYYY") will result in a date

Answer 5

SSIS Solution

The DT_DATE data type is implemented using an 8-byte floating-point number. Days are represented by whole number increments, starting with 30 December 1899, and midnight as time zero. Hour values are expressed as the absolute value of the fractional part of the number. However, a floating point value cannot represent all real values; therefore, there are limits on the range of dates that can be presented in DT_DATE. Read more

From the description above you can see that you can convert these values implicitly when mapping them to a DT_DATE Column after converting it to a 8-byte floating-point number DT_R8.

Use a derived column transformation to convert this column to 8-byte floating-point number:

(DT_R8)[dateColumn]

Then map it to a DT_DATE column

Or cast it twice:

(DT_DATE)(DT_R8)[dateColumn]

You can check my full answer here:

• Is there a better way to parse [Integer].[Integer] style dates in SSIS?

Answer 6

In postgresql, you can use the following syntax:

SELECT ((DATE('1899-12-30') + INTERVAL '1 day' * FLOOR(38242.7711805556)) + (INTERVAL '1 sec' * (38242.7711805556 - FLOOR(38242.7711805556)) * 3600 * 24)) as date

In this case, 38242.7711805556 represents 2004-09-12 18:30:30 in excel format

Answer 7

Google BigQuery solution

Standard SQL

Select Date, DATETIME_ADD(DATETIME(xy, xm, xd, 0, 0, 0),  INTERVAL xonlyseconds SECOND) xaxsa
from (
  Select Date, EXTRACT(YEAR FROM xonlydate) xy, EXTRACT(MONTH FROM xonlydate) xm, EXTRACT(DAY FROM xonlydate) xd, xonlyseconds
  From (
     Select Date
        , DATE_ADD(DATE '1899-12-30', INTERVAL cast(FLOOR(cast(Date as FLOAT64)) as INT64) DAY )   xonlydate
        , cast(FLOOR( ( cast(Date as FLOAT64) - cast(FLOOR( cast(Date as FLOAT64)) as INT64)  ) * 86400 ) as INT64) xonlyseconds
     FROM (Select '43168.682974537034' Date) -- 09.03.2018  16:23:28
   ) xx1
 )

Answer 8

I had to take this to the next level because my Excel dates also had times, so I had values like this:

42039.46406 --> 02/04/2015 11:08 AM
42002.37709 --> 12/29/2014 09:03 AM
42032.61869 --> 01/28/2015 02:50 PM

(also, to complicate it a little more, my numeric value with decimal was saved as an NVARCHAR)

The SQL I used to make this conversion is:

SELECT DATEADD(SECOND, (
                        CONVERT(FLOAT, t.ColumnName) - 
                        FLOOR(CONVERT(FLOAT, t.ColumnName))
                       ) * 86400,
               DATEADD(DAY, CONVERT(FLOAT, t.ColumnName), '1899-12-30')
              )

Answer 9

You can do this if you just need to display the date in a view:

CAST will be faster than CONVERT if you have a large amount of data, also remember to subtract (2) from the excel date:

CAST(CAST(CAST([Column_With_Date]-2 AS INT)AS smalldatetime) AS DATE)

If you need to update the column to show a date you can either update through a join (self join if necessary) or simply try the following:

You may not need to cast the excel date as INT but since the table I was working with was a varchar I had to do that manipulation first. I also did not want the "time" element so I needed to remove that element with the final cast as "date."

UPDATE [Table_with_Date]
SET [Column_With_Excel_Date] = CAST(CAST(CAST([Column_With_Excel_Date]-2 AS INT)AS smalldatetime) AS DATE)

If you are unsure of what you would like to do with this test and re-test! Make a copy of your table if you need. You can always create a view!

Answer 10

In addition of @Nick.McDermaid answer I would like to post this solution, which convert not only the day but also the hours, minutes and seconds:

SELECT DATEADD(s, (42948.123 - FLOOR(42948.123))*3600*24, dateadd(d, FLOOR(42948.123),'1899-12-30'))

For example

• 42948.123 to 2017-08-01 02:57:07.000
• 42818.7166666667 to 2017-03-24 17:12:00.000

Answer 11

Found this topic helpful so much so created a quick SQL UDF for it.

CREATE FUNCTION dbo.ConvertExcelSerialDateToSQL
(
    @serial INT
)
RETURNS DATETIME
AS
BEGIN
    DECLARE @dt AS DATETIME
    SELECT @dt = 
        CASE
            WHEN @serial is not null THEN CAST(@serial - 2 AS DATETIME)
            ELSE NULL
        END
    RETURN @dt              
END
GO

Answer 12

In SQL:

select dateadd(d,36464,'1899-12-30')
-- or thanks to rcdmk
select CAST(36464 - 2 as SmallDateTime)

In SSIS, see here

http://msdn.microsoft.com/en-us/library/ms141719.aspx

Answer 13

The marked answer is not working fine, please change the date to "1899-12-30" instead of "1899-12-31".

select dateadd(d,36464,'1899-12-30')

Answer 14

this actually worked for me

dateadd(mi,CONVERT(numeric(17,5),41869.166666666664)*1440,'1899-12-30') 

(minus 1 more day in the date)

referring to the negative commented post

Answer 15

This worked for me because sometimes the field was a numeric to get the time portion.

Command:

 dateadd(mi,CONVERT(numeric(17,5),41869.166666666664)*1440,'1899-12-31')