Change Excel date number to Oracle date

Question

I\'m having date as 41293 in oracle, how can i show it in DD/MON/YYYY format?

If i copy pasted it in Excel and change it to date format, i

Answer 1

Microsoft's Documentation

Excel stores dates as sequential serial numbers so that they can be used in calculations. January 1, 1900 is serial number 1, and January 1, 2008 is serial number 39448 because it is 39,447 days after January 1, 1900.

Excel has a bug feature where it considers 1900 to be a leap year and day 60 is 1900-02-29 but that day never existed and a correction needs to be applied for this erroneous day.

It does also state that:

Microsoft Excel correctly handles all other leap years, including century years that are not leap years (for example, 2100). Only the year 1900 is incorrectly handled.

Therefore only a single correction is required.

So:

• Before 1900-03-01 you can use DATE '1899-12-31' + value.
• On or after 1900-03-01 you can use DATE '1899-12-30' + value.

Which can be put into a CASE statement:

SELECT CASE
       WHEN value >=  1 AND value < 60
       THEN DATE '1899-12-31' + value
       WHEN value >= 60 AND value < 61
       THEN NULL
       WHEN value >= 61
       THEN DATE '1899-12-30' + value
       END AS converted_date
FROM   your_table

Answer 2

The value you have is the number of days since the 30th of December 1899. Try:

select to_char(
  to_date('1899-12-30', 'YYYY-MM-DD') + 41293,
  'DD/MON/YYYY') from dual

Answer 3

Quoting from Oracle forum:

You need a tool to do that, since format is to tell oracle what type of format you have on your date type in the spreadsheet. While you may not have opted to format the date in Excel, it will appear as a date in the previewer. Use the format from this as a guide to enter into the datatype panel.

so, if you have a date that looks like this in the previewer, 19-jan-2006, then your format for the data type panel if you choose to insert that column is going to be DD-MON-YYYY,

Option 1:

Try using the below functions

FUNCTION FROMEXCELDATETIME ( ACELLVALUE IN VARCHAR2 )
    RETURN TIMESTAMP
IS
    EXCEL_BASE_DATE_TIME CONSTANT TIMESTAMP
            := TO_TIMESTAMP ( '12/31/1899',
                           'mm/dd/yyyy' ) ;

    VAL CONSTANT NUMBER
            := TO_NUMBER ( NULLIF ( TRIM ( ACELLVALUE ),
                                '0' ) ) ;
BEGIN
    RETURN EXCEL_BASE_DATE_TIME
          + NUMTODSINTERVAL ( VAL
                          - CASE
                                WHEN VAL >= 60
                                THEN
                                    1
                                ELSE
                                    0
                            END,
                          'DAY' );
END;

FUNCTION TOEXCELDATETIME ( ATIMESTAMP IN TIMESTAMP )
    RETURN VARCHAR2
IS
    EXCEL_BASE_DATE_TIME CONSTANT TIMESTAMP
            := TO_TIMESTAMP ( '12/31/1899',
                           'mm/dd/yyyy' ) ;

    DIF CONSTANT INTERVAL DAY ( 9 ) TO SECOND ( 9 )
            := ATIMESTAMP
               - EXCEL_BASE_DATE_TIME ;
    DAYS CONSTANT INTEGER := EXTRACT ( DAY FROM DIF );
BEGIN
    RETURN CASE
              WHEN DIF IS NULL
              THEN
                  ''
              ELSE
                  TO_CHAR (  DAYS
                         + CASE
                               WHEN DAYS >= 60
                               THEN
                                   1
                               ELSE
                                   0
                           END
                         + ROUND ( ( EXTRACT ( HOUR FROM DIF )
                                  + ( EXTRACT ( MINUTE FROM DIF )
                                    + EXTRACT ( SECOND FROM DIF )
                                      / 60 )
                                    / 60 )
                                 / 24,
                                 4 ) )
          END;
END;

Option 2:

The excel function would be =TEXT(B2,"MM/DD/YY"), to convert an Excel date value stored in B2. Then try using the test character in Oracle

If considering 1900 Jan 1st as start date,

SELECT
      TO_CHAR ( TO_DATE ( '1900-01-01',
                      'YYYY-MM-DD' )
              + 41293,
              'DD/MON/YYYY' )
FROM
      DUAL