Q214623: PRB: Some SET CENTURY Options May Not Prevent Four Digit Dates

Article: Q214623
Product(s): Microsoft FoxPro
Version(s): 3.0b,5.0,5.0a,6.0
Operating System(s): 
Keyword(s): kbYear2000 kbvfp300b kbvfp500 kbvfp500a kbvfp600 kbXBase
Last Modified: 14-AUG-2001

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0b, 5.0, 5.0a, 6.0 
- Microsoft Visual FoxPro for Macintosh, version 3.0b 
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SYMPTOMS
========

The dates in text boxes might display the year with four digits even after
issuing SET CENTURY OFF in any version of Visual FoxPro or issuing a SET CENTURY
TO <value> ROLLOVER <value> in Visual FoxPro 5.0 or 6.0.

STATUS
======

This behavior is by design.

MORE INFORMATION
================

Beginning in Visual FoxPro 3.0, date values began appearing in four digits to
prevent any confusion regarding the correct century. This feature is called
Auto-Century. The Auto-Century feature ensures that any date written to a text
box has the century the user intended.

Auto-Century operates differently in various versions of Visual FoxPro. In Visual
FoxPro 3.0x and later with SET CENTURY OFF in effect, the text box displays four
digit dates whenever the year is greater than 1999. Visual FoxPro 5.0x and 6.0
display a four digit date even after issuing a SET CENTURY TO <value>
ROLLOVER <value> when the century portion of the date exceeds the SET
CENTURY TO value. Auto-Century ignores the ROLLOVER value.

Steps to Reproduce Behavior
---------------------------

1. In Visual FoxPro 3.0b, 5.0x, or 6.0, create a form with a text box called
  Text1.

2. Add a command button, and set the Caption property to 1959. In the Click
  event of the object, add the following code:

  ThisForm.Text1.Value={01/01/1959}

3. Add a second command button and set the Caption property to 2029. In the
  Click event of the object, add the following code:

  ThisForm.Text1.Value={01/01/2029}

4. Save the form and call it Zdatetest.

5. Activate the Command window and issue a "SET CENTURY OFF" (without the
  quotation marks) command.

6. Run the form. Click the buttons and observe the textbox.

The date appears in the text box in four digit form even though SET CENTURY is
set off.
NOTE: In Visual FoxPro 6.0, the Century property can be used to force a two-digit
date by setting it to 0 - Off.
To demonstrate how Auto-Century interacts with SET CENTURY TO <value>
ROLLOVER <value> command, which is available in versions of Visual FoxPro
after 3.0b, perform the following steps:

1. Perform steps 1 through 4 listed above.

2. Activate the Command window and issue a "SET CENTURY TO 19 ROLLOVER 70"
  (without the quotation marks).

3. Run the form.

In Visual FoxPro 5.x, the text box displays four digits whenever the century
portion of the year is greater than the SET CENTURY TO value. In Visual FoxPro
6.0, the textbox displays four year digits for both dates. Visual FoxPro ignores
the ROLLOVER value.

Running the example in Visual FoxPro 5.0x, the textbox reports the first date
{01/01/1959} as 01/01/59 because the century is equal to 19. However, 01/01/2029
appears in four digit form since the century of this date is equal to 20 while
SET CENTURY is set to 19. Note that the ROLLOVER value is ignored.

Running the same example in Visual FoxPro 6.0 displays 01/01/1959 and 01/01/2029
respectively.

REFERENCES
==========

For additional information about the ROLLOVER keyword available in Visual FoxPro
5.0x and later, please see the following articles in the Microsoft Knowledge
Base:

Q167186 PRB: SET CENTURY ROLLOVER Ignores Setting of SET CENTURY OFF

Q162388 HOWTO: Prepare for the Year 2000

Q190480 PRB: SET("Century",1) Not Reporting Correct Century


Additional query words:

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Keywords          : kbYear2000 kbvfp300b kbvfp500 kbvfp500a kbvfp600 kbXBase 
Technology        : kbHWMAC kbOSMAC kbVFPsearch kbAudDeveloper kbVFP300bMac kbVFP300b kbVFP500 kbVFP600 kbVFP500a
Version           : :3.0b,5.0,5.0a,6.0
Issue type        : kbprb

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