ID:MI Date not changing at 12:00am
Quarterdeck Technical Note #176
by Daniel Travison

  Periodically, a DESQview user who keeps his system on over a
24-hour period will discover that the system date did not change at
midnight.  Although this might appear to be a problem with
DESQview, it is really a problem caused by an application.  The way
DOS determines if the date has rolled over is by making a call to
interrupt 1Ah using function 0.

  One piece of information returned is the number of times the date
has rolled over since the last time the call was made.  The call
ALSO resets the flag that indicates the date has rolled over to 0. 
The problem occurs when an application makes this call before DOS
gets a chance to see the date rollover.  The flag gets reset to
zero and DOS does not change the date.

  A second problem that can occur is due to a bug in DOS.  DOS
considers the above flag as an indication that the date changed. 
Many BIOSes, however, use this flag to count how many times the
date has changed.  If you were to leave your system running over
the weekend and none of the applications running asked DOS for the
date, when you come back to the system Monday morning, the system
date would not be correct.

  For example:

  When you turn the system on Friday, this flag is set to zero
  Saturday morning, the flag gets set to 1
  Sunday morning, the flag is set to 2
  Monday morning, the flag is set to 3
  Monday morning you type DATE at a DOS prompt, the date will set
  for the Saturday instead of Monday.

  DOS simply checks to see if the flag is not 0, and increments the
Date instead of seeing what the flag's value is and adjusting the
date based on that value.

   The solution to the problem is to run a program that asks DOS
for the date.  One of the programs on Quarterdeck's BBS is called
DVTIME.COM.  This program simply asks DOS for the date and time
once a second and displays it in a small window.  It is written to
make use of DESQview's Timer Object which allows it to have
DESQview wake it up, read the time, and 'go back to sleep.'  This
might be just the program you need if you are allowing your system
to run over extended periods of time and experience the above
problem.

        Copyright (C) 1991 by Quarterdeck Office Systems
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