Microsoft KB Archive/163915

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INFO: The Year 2000 Problem Under Japanese Windows NT

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Q163915

The information in this article applies to:


 * Microsoft Win32 Software Development Kit (SDK) on the following platform:
 * Windows NT, Japanese, version 3.5, 3.51, 4.0

SUMMARY
This article describes the year 2000 problem under Windows NT specific to PC/AT-compatible computers.

MORE INFORMATION
This article describes Microsoft's workaround for the year 2000 problem specific to Windows NT running on PC/AT-compatible computers.

A PC/AT-compatible computer uses Real Time Clock (RTC) to control the data and time values. By reading the complementary metal-oxide semiconductor (CMOS) index, you can obtain the following RTC time values:

 RTC TimeRetrieved Value - Second:0 Minute:2 Time:4 Day-of-Week:6 Date:7 Month:8 Year (Last 2 digits):9 Year (First 2 digits):32h As shown above, the last value "Year (First 2 digits)" was added later.

Depending on the computers that are currently released, this value is handled differently according to the following three classified patterns:

Pattern 1

 * For the "Year (First 2 digits)", the value that is read from the CMOS is hold, but carrying from the "Year (Last 2 digits)" does not occur.

Pattern 2

 * For the "Year (First 2 digits)", 19 is always returned.

Pattern 3

 * For the "Year (First 2 digits)", the value that is read from the CMOS is hold, and carrying from the "Year (Last 2 digits)" occurs.

Windows NT 3.5 (SP2) and 3.51 (SP3, SP4) use the "Year (First 2 digits)" value retrieved from the CMOS "as is."

As a result, if the computer you use performs the Pattern 3, Windows NT 3.5 (SP2) or 3.51 (SP3, SP4) works properly. However, if the computer you use performs any pattern other than Pattern 3, a problem might occur.

Windows NT 3.51 (SP3, SP4) is designed to synchronize the internal time value and the RTC-retrieved value every hour, which causes the system time to be updated to match with the RTC time.

Microsoft considers this behavior to be a hardware problem that should be handled by a hardware vendor. However, considering the fact that there are still many Windows NT users who use the computers that perform Pattern 1 or Pattern 2, Microsoft designed Windows NT 3.51 Service Pack 5 and Windows NT 4.0 to add 100 years to the RTC-retrieved value if it is between 1900 and 1920 so that you can work around this behavior.

Again, this workaround is not adapted to Japanese Windows NT 3.5 (Service Pack 2 included) and Windows NT 3.51 Service Pack 3 or 4, and is not scheduled to fix. If you the CMOS on your computer performs either Pattern 1 or Pattern 2, you should upgrade your Windows NT to Windows NT 3.51 Service Pack 5 or to Windows NT 4.0, if possible.

To know what pattern your computer (CMOS) performs, please consult your hardware manufacture. For any application-specific problems, please consult your application vendor.

For more information about how Microsoft products are affected by year 2000 (Y2K) issues, please see the following Microsoft World Wide Web site:

"http://www.microsoft.com/technet/year2k/product/product.asp" Additional query words:

Keywords : kbYear2000 kbIntl

Issue type : kbinfo

Technology :