PRB: LocalFileTimeToFileTime may not Return Correct UTC Time

ID: Q180104

The information in this article applies to:

Extended Messaging Application Programming Interface (MAPI), version 1.0

SYMPTOMS

The LocalFileTimeToFileTime() function in Mapi.dll may not return the correct time when the function is executed on a computer running Windows 95 or Windows NT.

CAUSE

The 16-bit version of the LocalFileTimeToFileTime function in Mapi.dll gets time zone information from the Win.ini file instead of the registry.

RESOLUTION

The time zone information is not written to the Win.ini file in Windows 95 or Windows NT. However, you may add the time zone information to the Win.ini file. The information to be added is at the following location in the registry:

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation

You need to modify the Win.ini file by adding the following section:

   [MAPI 1.0 Time Zone]

The user needs to copy the values and data for each entry in the registry key listed above to a separate line into this section of the Win.ini. The end user should then have a Win.ini file that has the following section with similar data as shown below:

   [MAPI 1.0 Time Zone]
   Bias=12c
   StandardName=Eastern Standard Time
   StandardBias=0
   StandardStart=00000A00050002000000000000000000
   DaylightName=Eastern Daylight Time
   DaylightBias=ffffffc4
   DaylightStart=00000400010002000000000000000000
   ActiveTimeBias=12c

STATUS

This behavior is by design.

MORE INFORMATION

LocalFileTimeToFileTime() is used to convert a local file time to a file time based on the Coordinated Universal Time (UTC). The function uses the current computer settings for the time zone and daylight saving time.

Keywords          : kbMsg kbMAPI100 
Version           : WINDOWS:1.0
Platform          : WINDOWS
Issue type        : kbprb

Last Reviewed: February 1, 1998