modification to winbase.bi

[andykmv]

i have been working on a project processing date time records from a system and I needed time zone information to aid processing this data.

the information i needed to access include the current time zone name (in my case, AUS Eastern Standard Time or AEST) and whether or not i am currently in daylight saving or not - either AUS Eastern Standard Time (AEST) or AUS Eastern Daylight time (AEDT).

The functions that provided the answers i needed are part of the following winapi:
https://msdn.microsoft.com/en-us/librar ... s.85).aspx
The documentation state that this function is valid for windows vista as a minimum, and the OS this app will be used on is windows 8 and above.

In freebasic's winbase.bi the necessary function is wrapped by the macro "#if _WIN32_WINNT = &h0602", and the function i needed is "GetDynamicTimeZoneInformation". The data i needed is in the content of the data structure, and by default this function is not accessible in win8+ 64bit. Here is the relevant section of the winbase.bi which includes my modification just before the macro:

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#define _TIMEZONEAPI_H_
const TIME_ZONE_ID_INVALID = cast(DWORD, &hffffffff)

type _TIME_ZONE_INFORMATION
	Bias as LONG
	StandardName as wstring * 32
	StandardDate as SYSTEMTIME
	StandardBias as LONG
	DaylightName as wstring * 32
	DaylightDate as SYSTEMTIME
	DaylightBias as LONG
end type

type TIME_ZONE_INFORMATION as _TIME_ZONE_INFORMATION
type PTIME_ZONE_INFORMATION as _TIME_ZONE_INFORMATION ptr
type LPTIME_ZONE_INFORMATION as _TIME_ZONE_INFORMATION ptr

type _TIME_DYNAMIC_ZONE_INFORMATION
	Bias as LONG
	StandardName as wstring * 32
	StandardDate as SYSTEMTIME
	StandardBias as LONG
	DaylightName as wstring * 32
	DaylightDate as SYSTEMTIME
	DaylightBias as LONG
	TimeZoneKeyName as wstring * 128
	DynamicDaylightTimeDisabled as WINBOOLEAN
end type

type DYNAMIC_TIME_ZONE_INFORMATION as _TIME_DYNAMIC_ZONE_INFORMATION
type PDYNAMIC_TIME_ZONE_INFORMATION as _TIME_DYNAMIC_ZONE_INFORMATION ptr
declare function SystemTimeToTzSpecificLocalTime(byval lpTimeZoneInformation as const TIME_ZONE_INFORMATION ptr, byval lpUniversalTime as const SYSTEMTIME ptr, byval lpLocalTime as LPSYSTEMTIME) as WINBOOL
declare function TzSpecificLocalTimeToSystemTime(byval lpTimeZoneInformation as const TIME_ZONE_INFORMATION ptr, byval lpLocalTime as const SYSTEMTIME ptr, byval lpUniversalTime as LPSYSTEMTIME) as WINBOOL
declare function FileTimeToSystemTime(byval lpFileTime as const FILETIME ptr, byval lpSystemTime as LPSYSTEMTIME) as WINBOOL
declare function SystemTimeToFileTime(byval lpSystemTime as const SYSTEMTIME ptr, byval lpFileTime as LPFILETIME) as WINBOOL
declare function GetTimeZoneInformation(byval lpTimeZoneInformation as LPTIME_ZONE_INFORMATION) as DWORD

'-- mod by as on 2 aug 2018 - pulling next func decl from next #if _win32... section------------------------------
declare function GetDynamicTimeZoneInformation(byval pTimeZoneInformation as PDYNAMIC_TIME_ZONE_INFORMATION) as DWORD
'-- mod by as on 2 aug 2018 - pulling next func decl from next #if _win32... section------------------------------

#if _WIN32_WINNT = &h0602
	declare function GetDynamicTimeZoneInformation(byval pTimeZoneInformation as PDYNAMIC_TIME_ZONE_INFORMATION) as DWORD
	declare function GetTimeZoneInformationForYear(byval wYear as USHORT, byval pdtzi as PDYNAMIC_TIME_ZONE_INFORMATION, byval ptzi as LPTIME_ZONE_INFORMATION) as WINBOOL
	declare function EnumDynamicTimeZoneInformation(byval dwIndex as const DWORD, byval lpTimeZoneInformation as PDYNAMIC_TIME_ZONE_INFORMATION) as DWORD
	declare function GetDynamicTimeZoneInformationEffectiveYears(byval lpTimeZoneInformation as const PDYNAMIC_TIME_ZONE_INFORMATION, byval FirstYear as LPDWORD, byval LastYear as LPDWORD) as DWORD
	declare function SystemTimeToTzSpecificLocalTimeEx(byval lpTimeZoneInformation as const DYNAMIC_TIME_ZONE_INFORMATION ptr, byval lpUniversalTime as const SYSTEMTIME ptr, byval lpLocalTime as LPSYSTEMTIME) as WINBOOL
	declare function TzSpecificLocalTimeToSystemTimeEx(byval lpTimeZoneInformation as const DYNAMIC_TIME_ZONE_INFORMATION ptr, byval lpLocalTime as const SYSTEMTIME ptr, byval lpUniversalTime as LPSYSTEMTIME) as WINBOOL
#endif

i used this code to access the information:

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#include "windows.bi"		'includes my modified winbase.bi
Dim DynamicTimeZoneInfo As DYNAMIC_TIME_ZONE_INFORMATION
Dim as double _ReturnValue

' The return value (0|1|2) tells me if i am currently in daylight savings time or not
_ReturnValue=GetDynamicTimeZoneInformation(@DynamicTimeZoneInfo)
Print  "_ReturnValue=";_ReturnValue

' And the current time zone name is stored in the TimeZoneKeyName value
Print DynamicTimeZoneInfo.TimeZoneKeyName

While the modification works fine for me, can a change be made to the default winbase.bi to include this function ?
I haven't worked out a suitable macro wrapper as yet (I'll start looking at this - suggestions ?).

[Josep Roca]

There is not need to modify anything. Just add #define _WIN32_WINNT &h0602 before #include "windows.bi".

[andykmv]

There is not need to modify anything. Just add #define _WIN32_WINNT &h0602 before #include "windows.bi".

(smacks forehead) bingo! thanks for that @Josep Roca - i feel like i am starting to get a handle on using third party and ms libraries now!