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Q139835: FIX: TTOD() Returns Incorrect Date with Time of 12:00:00 AM

Article: Q139835
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0
Operating System(s): 
Keyword(s): kbvfp kbvfp500fixkbbuglist kbfixlist
Last Modified: 24-MAR-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
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SYMPTOMS
========

When you use TTOD() on a variable containing a time of 12:00:00 AM, TTOD()
returns an incorrect date. If one second is added to the date value, TTOD()
returns the correct date.

CAUSE
=====

12 AM is considered to be the start of a new day, so at 12 AM, TTOD() should
display the date for the next day. However, TTOD() miscalculates and incorrectly
displays the date for the previous day.

STATUS
======


Microsoft has confirmed this to be a problem in the Microsoft products listed at
the beginning of this article. This problem has been fixed in Visual FoxPro 5.0
for Windows.

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

The TTOD() function returns a date value from a datetime function or value.

Steps to Reproduce Problem
--------------------------

In the following example, a variable is set to 10/24/95 at 10 PM. Two hours are
added to the value, one at a time. Then the date is checked to make sure it has
switched to 10/25/95 12:00:00 AM.

In the Command window, type the following commands:

  x = {10/24/95 22:00:00} && Initialize date variable to 10 PM Oct 24, 1995
  ? type("x")             && Should return 'T' for DateTime
  ?x                      && Should return 10/24/95
  x=x+3600                && Add one hour to the time
  ?x                      && Should display 11 PM on Oct 24, 1995
  x=x+3600                && Add another hour to the time
  ?x                      && Should display 12 AM Oct 25, 1995
  ?ttod(x)                && Will display 10/24/95 when you expect 10/25/95

The following two lines show that adding one second to 10/25/95 12:00:00 AM does
allow TTOD() to return 10/25/95 as expected:

  x=x+1                   && Add one second for 12:00:01 AM Oct 25, 1995
  ?ttod(x)                && Should return 10/25/95

Additional query words: date

======================================================================
Keywords          : kbvfp kbvfp500fix kbbuglist kbfixlist
Technology        : kbVFPsearch kbAudDeveloper kbVFP300
Version           : WINDOWS:3.0
Issue type        : kbbug
Solution Type     : kbfix

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