Microsoft Year 2000 Readiness Disclosure & Resource Center

Product Summary

Product: Excel 5.0 Version: Category: Compliant# Operating System: 16-Bit Win Language: Polish Release Date: 31 Aug 1994 Operational Range: 01 Jan 1900 - 31 Dec 2078 Prerequisites: None Product Dependencies: Microsoft Windows 3.1 or above or Microsoft Windows NT 3.1 or above Clock Dependencies: System clock Last Updated: 19 May 1999

Product Details

How the product handles dates: Storage. Microsoft Excel stores dates as numeric values, with day #1 being 01/01/1900. . Excel 5 recognizes 01-JAN-1900 through 31-DEC-2078 as valid dates. 01/01/2000 is stored as value 36526, since it is the 36526th day in the century. Formatting. When Microsoft Excel formats a date, it uses one of several default formats. The most common is the system short date. If the system short date is a YY format (2-digit year), then even when the user types a YYYY date (4-digit year), it will by default display in a YY format. The format can be changed. To avoid any ambiguity we recommend changing the system short date to a YYYY format. Parsing on date entry. If a user enters a date in a "M/d/yy" format, less than 20 is 20XX, and equal to or greater than 20 is 19XX. For example, Excel 5 will recognize, "01/01/15" as January 1, 2015, but will recognize "01/01/25" as January 1, 1925. To avoid any possible confusion, users can always display dates in a YYYY format so the century is clearly shown Leap Year. Microsoft Excel treats 1900 as a leap year for backward compatibility with other products such as Lotus 1-2-3. (See Knowledge Base article Q181370 for more information.) Two-digit shortcut handling: See discussion above. Conversion of 2-digit shortcut dates assumes a date window of 1920 through 2019. (See Knowledge Base (KB) article Q164406 for more information.) What are the acceptable deviations? MS Query accepts two-digit year date formatting for your ODBC query, but will always assume a twentieth century date. To avoid this issue, you should always use four digit years for queries based upon date data. 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, you have the date January 1, 1915. You copy the date, but your system settings are "M/d/yy", and all that is copied is the text "1/1/15". When you paste "1/1/15" into Microsoft Excel, it will parse the date to January 1, 2015. Such an error 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 KB articles Q182766 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 you 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 only records the year according to the system short date format, which results in parsing a 2-digit year in playback. (See KB article Q182766 for more information.) Using a format such as "Dec 98" will not function correctly at the year 2001. This is because 98 is too large to be the day of month, so Microsoft Excel assumes it is a year. However, Excel assumes "Dec 01" refers to December 1 of the current year. Since Microsoft Excel always stores the complete date, you can avoid ambiguity by entering a full date regardless of the display formatting. (See KB article Q180952 for more information.) Microsoft Excel handles serial dates, the most common usage of dates, properly. Due to the ambiguous nature of text dates, there is always some potential for error. 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 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 never 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 "2/1/25" could be interpreted as Feb. 1, 1925, Jan. 2, 1925, Feb. 1, 2025, or Jan. 2, 2025. 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 and recommendations: In general, avoid testing in a production environment or with non-duplicated production files because we cannot predict side effects with other products. 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 2Y dates in text file formats such as TXT, DIF, CSV, 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 years will be parsed with the 2019/1920 cutoff. This is different from later versions of Excel, so use 4-digit years 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.           VB/VBA   Transfer between VB/VBA and cells   Internally, VBA 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.

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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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