Microsoft Year 2000 Readiness Disclosure & Resource Center

Product Summary

Product: Excel 95 Version: 7.0 Category: Compliant# Operating System: 32-Bit Win Language: Vietnamese Release Date: 10 Sep 1996 Operational Range: 01 Jan 1900 - 31 Dec 2078 Prerequisites: none Product Dependencies: Microsoft Vietnamese Windows 95 Clock Dependencies: System Clock Last Updated: 14 Oct 1999

Product Details

What are the issues with this product? MS Query accepts 2-digit year date formatting for the userÆs ODBC query, but assumes a date in the 1900s. To avoid this issue, users should use 4-digit years for queries based upon date data. How the product handles dates: Storage. Microsoft Excel stores dates as numeric values, with day #1 being 1/1/1900. The day number for any date in history stays the same regardless of the format in which the date is displayed. Excel 95 recognizes 01-Jan-1900 through 31-Dec-2078 as valid dates. Visual Basic/Visual Basic for Applications use the same serial date system, with the exception of 1-Jan-1900 through 28-Feb-1900, where the values are different by 1, as a result of a backward-compatibility issue for a bug in Lotus 1-2-3 that treats 1900 as a leap year. December 31, 1999 is stored as day #36525 in Excel even though there are only 36524 days in the 1900s. 2-Digit year entries. Excel adds 1900 or 2000 to 2-digit year entries so that all such entries will be stored as years between 1920 and 2019, inclusive. This will be called the 2019/1920 cutoff rule. 00 to 19 is interpreted as 20xx (2000 to 2019) 20 to 99 is interpreted as 19xx (1920 to 1999) Formatting. Vietnamese Excel 95 will format the date entered in a cell according to the Short Date Style set in the Regional Settings of the Control Panel. If the system short date is a yyyy (4-digit year) format, when the user types a yy date (2-digit year format), it will by default display in a yyyy format according to the 2019/1920 cutoff rule. Common Date Usage Errors: If a date is pasted from one application to another using only the last two digits of the year, Microsoft Excel might parse the date differently than the originating application calculated it. Example: In a non-Excel application, the user has the date January 1, 1915. When copying the date, the system settings are "M/d/yy", and the text that is copied is "1-1-15". When the user pastes "1-1-15" into Microsoft Excel, it will parse the date to January 1, 2015. Such a misinterpretation can also occur when one application is using a "M/d/yy" format while another application is using a "d/M/yy" format. This also applies to importing dates from text files. (See Knowledge Base article Q180159 for more information.) The DATE() function is not designed to take 2-digit year shortcuts since it receives numeric parameters. The DATE() function calculates a number less than 1900 as an offset from 1900. So, if the user were to enter a formula such as =DATE(15,1,1), the resulting date would be January 1, 1915, not 2015.  Recording date entry in a macro records/plays back the year in yy format even if the user enters yyyy and even if the system short date format was yyyy. For example if the system date was MM/dd/yyyy and the user records a macro which enters in a cell the date 12/12/2025, Vietnamese Excel 95 will play it back as 12/12/1925. This may cause problems if the two-digit year is not meant to follow the 1920-2019 date window that is mentioned above. See Knowledge Base article Q180159 for more information. Recommendations: Due to the ambiguous nature of text dates, use serial dates whenever possible and take great care when transferring text dates. Change the default system short date format to include a 4-digit year. Get in the habit of using 4-digit year formats for dates in Microsoft Excel. Such a practice will make the date visible if a user mistakenly enters a date in the wrong century. When dates must be transferred between applications, ideally they should be transferred as serial dates. They should not be transferred as an ambiguous text format that doesnÆt specify the century and causes confusion between month and day-of-month. For example, the text "2/1/15" could be interpreted as Feb. 1, 1915, Jan. 2, 1915, Feb. 1, 2015, or Jan. 2, 2015. Defined names store references only as text strings. Since they do not store dates as serial values, they are vulnerable to century issues when a 2-digit year format is used. Using defined names in this way is also problematic because users who use a date format with an order other than M-d-y will experience miscalculations. Recommended usage is to define the name referring to a cell containing a serial date, which will avoid both of the above-mentioned potential problems. Testing guidelines: In general, avoid testing in a production environment or with non-duplicated production files because side effects with other products are difficult to predict. Interoperability testing with other Microsoft Office products can be conducted safely. The following areas should be examined to verify whether dates are being properly used. The table below can be used to guide testing of Microsoft Excel within your organization. Sub-system Component File Various File Formats Avoid storing 2-digit dates in text file formats such as TXT, DIF, CSV, and PRN. The default column width with default fonts may truncate characters with date formats that have 8 digits and two separators. To correct, increase the column width, or change the font to a fixed-width typeface such as Courier New. Data Import from: text, Databases, External data sources Sort Data imported from databases and other external sources is often imported as text. Importing 2-digit dates will be parsed with the 2019/1920 cutoff. This is different from previous versions of Excel, so use 4-digit dates to prevent confusion. Basic Use Functions Date Entry Natural Language Functions Functions referring to text dates will parse according to the 2019/1920 cutoff rule. Date entry will parse according to the 2019/1920 cutoff rule. Visual Data Charts Since chart labels are normally used for display, and not for calculation, this shouldn't pose much of an issue. Visual Basic/Visual Basic for Applications Transfer between VB/VBA and cells Internally, Visual Basic for Applications treats dates as serial values, exactly like Excel. However, since VBA uses the "M/d/yy" format, you should avoid transferring the date text through VBA, since it could parse to the wrong century. This will also help avoid issues with international users who have a system short date format with an order other than M-d-y.   Additional Testing: Microsoft understands that for various reasons customers may be required to conduct their own year 2000 certification testing. Microsoft provides the tests below to aid customers in conducting their own year 2000 certification of Microsoft Excel. Excel is designed to handle 2-digit year shortcuts well into the next century. Dates are always stored internally, in a complete form, with full century information. Nevertheless, a user or administrator may elect to change the operating system short date format to a 4-digit display in order to avoid any ambiguity when reading or transferring dates. Note that this change can affect column widths and print layout and it could require additional changes in your worksheets. If the user decides not to set the system short date format to include a 4-digit year, the user can format each cell individually by selecting Format/Cells/Number/Custom, and entering a 4-digit year format. To change the system short date format, press the Start button, then select Settings, Control Panel, Regional Settings, select the Date page, then change the Short Date Style to a format that includes a 4-digit year by replacing the "yy" portion with "yyyy". Verify that Vietnamese Excel 95 transitions smoothly into the year 2000 when the Locale in Regional Settings is one of the Vietnamese countries: Warning! Before conducting this test, make sure there is not software containing a license that expires by the year 2000. This is especially common with beta copies of software programs. If a program determines that its license has expired it is possible the program will no longer boot, even after resetting the system clock. Changing a system clock on a network can affect other computers connected to the network, so it is highly recommended that the user isolate the computer from other systems before changing the system clock to conduct the following test. Set the system clock to 11:59 p.m. December 31, 1999. Start Vietnamese Excel 95. In cell A1 (cell R1C1 if in R1C1 mode), enter =NOW(). After one minute, press {F9} to recalculate the formula you entered in A1. Note that the time and date shown will be January 1, 2000, and nothing unusual has happened to Microsoft Excel. Remember to reset the system clock to the correct time and date after conducting this test. Verify that Microsoft Excel recognizes the year 2000 as a leap year: Start Excel. In cell A1 (cell R1C1 if in R1C1 mode), enter "=DATE(2000,2,28)+1". Note that the resulting date is February 29, indicating that Excel correctly recognizes that 2000 is a leap year. Note: The year 1900 is not a leap year. However, in testing you may notice Microsoft Excel treats 1900 as a leap year. This algorithm was adopted to maintain compatibility with dates in Lotus 1-2-3, and is by design. The calculation for leap years used by the Gregorian calendar is as follows. If a year is evenly divisible by four, it is a leap year, unless the year is evenly divisible by 100. If a year is evenly divisible by 100, it is not a leap year, unless it is also evenly divisible by 400. (See KB article Q181370 for more information.) Excel 95 uses a number of Microsoft Office 95 shared files for the implementation of dialogs and toolbars, task automation, online help, installation, graphics, file find and file I/O. For additional information that is appropriate for Excel 95, please refer either to the document for the particular Office version that this application came with, or, in the case of a standalone product, to any version 95 Microsoft Office document.

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ANY MICROSOFT YEAR 2000 STATEMENTS MADE TO YOU IN THE COURSE OF PROVIDING YEAR 2000 RELATED UPDATES, YEAR 2000 DIAGNOSTIC TOOLS, OR REMEDIATION SERVICES (IF ANY) ARE SUBJECT TO THE YEAR 2000 INFORMATION AND READINESS DISCLOSURE ACT (112 STAT. 2386). IN CASE OF A DISPUTE, THIS ACT MAY REDUCE YOUR LEGAL RIGHTS REGARDING THE USE OF ANY SUCH STATEMENTS, UNLESS OTHERWISE SPECIFIED BY YOUR CONTRACT OR TARIFF.

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