2. If you're still using a version of FileMaker prior to 3.0, upgrade it to FileMaker Pro version 3.0 or later.

Before installing any updates or patches which may alter your computer's operating system software or application programs, and before making any changes to your critical documents (data files), be sure that you have a complete, current backup of your computer's data. For general backup advice, see the Berkeley Computing and Communications articles Ask Dr. Micro: How can I back up the files on my computer and Simplify your life with the UCBackup service .

In FileMaker Inc.'s Year 2000 Readiness Q&A document, the vendor notes that, while there is no Y2K-specific update available for versions of FileMaker Pro prior to 3.0:

we are allowing customers with FileMaker Pro 2.1 or earlier versions to upgrade to FileMaker Pro 3.0.

The following information regarding the availability of this upgrade appeared on Ric Ford's MacInTouch Web site on September 10, 1999. (We have not independently verified this information.):

Rahm Tamir notes that FileMaker Inc. is offering free FileMaker Pro 3 upgrades to owners of earlier versions of the database application, in order to ensure that all users have a Year 2000-compliant version:

"Call 800-325-2747, hit the option for replacement manuals and disks, don't let them give you the number for the upgrade center (that's for paid upgrades only), and ask them to look into it. They'll put you on hold if they're not familiar with the situation, and come back on the line offering a free upgrade, shipping charges only."

When performing this upgrade, be sure to read the vendor's discussion of the differences between version 3.0 and earlier versions of FileMaker Pro in the vendor's Year 2000 Readiness Q&A .

As FileMaker Inc. points out:

Upgrading to FileMaker Pro 3.0v5 (Macintosh) and FileMaker Pro 3.0v6 (Windows) will involve data conversion, and possibly database design modifications.

What are the Y2K issues affecting versions 2.1 and earlier of FileMaker?

The vendor implies in their Year 2000 Readiness Q&A document - although they do not appear to state this outright - that no detailed information regarding Y2K issues affecting FileMaker versions 2.1 and earlier will be forthcoming. We do not know to what degree, if any, the vendor has tested any of these versions for Y2K issues.

In the vendor's Year 2000 Readiness Disclosure: FileMaker Products , when we checked it on September 20, 1999, there is a single statement regarding the date handling behavior of these earlier versions:

FileMaker Pro versions 2.1 and all earlier versions do not expand two-digit years [to four-digit years] at all.

4. (Optional, but highly recommended) In the case of critical data, enable "strict" validation for date fields to require that dates be entered with four-digit years.

After you have updated the FileMaker Pro application program to the latest release , you will for the first time be able to take advantage of a new "strict" data validation option which requires that dates be entered into date fields with full, four-digit years.

We strongly recommend that FileMaker users on the UC Berkeley campus enable this data validation option for critical date fields. This option will help ensure that:

• Dates are entered accurately into these date fields.
  
  
• Dates will not be at risk of changing centuries when they are later edited.

Here's how to enable this data validation option when using the Macintosh versions of FileMaker Pro:

1. Select "Define Fields..." from the File menu.
   
   
2. In the "Define Fields for <name of your database>" window, select (click on) the name of a date field for which you wish to enable this data validation option.
   
   
3. Click the "Options..." button.
   
   
4. In the "Entry Options for Field <name of this date field>" dialog, select "Validation" from the pop-up menu.
   
   
5. Click the "Strict data type" checkbox. ("4-Digit Year Date" should then appear in the pop-up menu to the right.)
   
   
   
   
6. Click "OK" in the "Entry Options" dialog.
   
   
7. Click "Done" in the "Define Fields" window.

After making this change, if a user of a FileMaker Pro database attempts to enter a date with a two-digit year into a date field, they will encounter a dialog similar to the following:

You can also combine this new four-digit-year validation option with other data validation options to further guard against the possibility of having incorrect dates entered into Date fields. For instance, you might wish to specify that dates must be entered with full four-digit years and that dates must fall within a specific range.

2. Watch out for dates which "switch centuries" when you edit them, either manually or via a script.

Two-digit-year dates stored in Date fields in FileMaker Pro database records remain "live" and are subject to being assigned to either the 20th or 21st Century each time they are modified. Under a narrow set of circumstances, these dates can "switch centuries" upon being edited.

This can occur when:

1. You are using a copy of the FileMaker Pro 3.0, 4.0, or 4.1 application program that has not yet been updated to the current release , and thus does not include the vendor's Y2K-related date-handling fixes.
   
   (The latest FileMaker Pro releases which incorporate these fixes - 3.0v5 [Macintosh] and 3.0v6 [Windows], 4.0v3, and 4.1v3 - do not appear to be at risk for this problem.)
   
   and
   
   
2. During the 1990s ...
   
   ... dates with two-digit years from "10" through "89" were stored in a Date field in a FileMaker Pro database.
   
   Examples of these dates - which would have been intended to fall within the period from 1910 through 1989 - include "1/15/10", "12/05/45", and "12/31/89".
   
   and
   
   
3. During the year 2000 or beyond...
   
   ... you later open this database and edit one or more of these dates, either manually or via a script.

When dates with two-digit years in the range from "00" through "89" are edited during the year 2000 or beyond, they are at risk of switching centuries, from the 1900s to the 2000s. For instance, the two-digit-year date "1/31/83", representing January 31, 1983, and having been originally entered into a Date field in a FileMaker Pro database record sometime during the 1990s, is at risk for being changed to "1/31/2083" upon being edited during the year 2000 or beyond, whether manually or by a script.

The following is a more detailed description of this scenario:

1. During the 1990s, you or someone else entered the date 1/31/83 into a Date field, representing January 31, 1983.
   
   
2. During the year 2000 or beyond, you then edit this date.
   
   This edit can be quite minor: perhaps you might make a correction to the day or month, or perhaps you even inadvertently delete a digit or slash, then immediately retype the same character.
   
   
3. You then click in another field or press the Tab key to move to another field.
   
   
4. Immediately, FileMaker Pro will once again interpret the two-digit year and assign this date to a century.
   
   Because FileMaker Pro will be using a different rule for assigning two-digit-year dates in the range from "10" through "89" to a century when the year 2000 arrives, compared with the rule it used during the 1990s, these dates will switch centuries, from the 1900s to the 2000s. Thus, in this example, FileMaker Pro will immediately change this date to 1/31/2083.

Fortunately, as far as we're aware, if a date is inadvertently switched from the 20th to 21st centuries, this change should be readily apparent, as FileMaker Pro versions 3.0 and above will instantly expand all 21st century dates to display the full four-digit year. For this reason, you should immediately see a date such as "1/31/83" or "01/31/1983" change to "1/31/2083" or "01/31/2083" after being edited, a highly evident transformation. Still, it may be possible for someone who is manually editing dates in date fields to miss seeing one or more such changes, or to fail to recognize the new dates as erroneous.

In addition, a related concern is that scripts which edit dates may also inadvertently cause some dates originally entered with two-digit years to switch centuries. Such script-triggered changes might not be so readily apparent.

Why does this behavior occur?

Reassigning two-digit-year dates to a particular century every time such dates are edited is an intentional (and documented) date-handling behavior of FileMaker Pro. As the vendor notes in its Year 2000 Readiness Disclosure: FileMaker Products , when we checked it on September 17, 1999:

Two-digit year dates are subject to interpretation at the time they are entered or modified.
(Our emphasis.)

Why are the latest releases of FileMaker Pro not subject to this problem?

If you are using the latest, updated releases of the FileMaker Pro application program - 3.0v5 (Macintosh) and 3.0v6 (Windows), 4.0v3, and 4.1v3 - you are unlikely to encounter this problem. This is because the latest releases of FileMaker Pro expand all dates with two-digit years to four-digit years when they are first entered into Date fields. In addition, these latest FileMaker Pro releases appear to automatically expand all two-digit-year dates in Date fields to four-digit-year dates when opening database files originally created using earlier releases of FileMaker Pro.

(These dates will all be expanded to years in the 1900s. According to the vendor's Year 2000 Readiness Q&A , when we checked it on September 20, 1999: All 2-digit year dates will be expanded to 19xx.)

As a result of this automatic date expansion when using the latest, updated releases of FileMaker Pro, dates in Date fields should all have four digit years, and thus are longer be at risk of "switching centuries" upon being edited.

In contrast, according to the vendor's Year 2000 Readiness Disclosure: FileMaker Products , earlier releases of FileMaker Pro 3.0, 4.0, and 4.1 do not expand two-digit-year dates which fall within the 20th Century, while FileMaker versions 2.1 and earlier do not expand any two-digit-year dates.

4. Be on the lookout for "dates" stored in Text fields.

If dates with century-ambiguous two-digit years have been stored in a Text field in a FileMaker Pro database, this could cause problems in which these dates are assigned to an incorrect century, either when they are converted to actual dates, or when they are exported to another program.

As one example, FileMaker Pro's TextToDate() function appears to always assume text dates with two-digit years fall into the 1900s. Even if you've entered a "date" such as "05/13/00" into a Text field, intending for this date to represent May 13, 2000; the TextToDate() function will instead interpret that date as May 13, 1900.

To avoid such problems, avoid storing dates in Text fields. Always use Date fields instead.