Convering UTC to Local Time and Vice Versa

Delphi/Pascal

function UTCToLocalTime(AValue: TDateTime): TDateTime; function LocalTimeToUTC(AValue: TDateTime): TDateTime;   function UTCToLocalTime(AValue: TDateTime): TDateTime; var   SysTime1, SysTime2: TSystemTime;   TZinfo: TTimeZoneInformation; begin   GetTimeZoneInformation(TZinfo);   DateTimeToSystemTime(AValue, SysTime1);   SystemTimeToTzSpecificLocalTime(@TZinfo, SysTime1, SysTime2);   Result := SystemTimeToDateTime(SysTime2); end;   function LocalTimeToUTC(AValue: TDateTime): TDateTime; var   SysTime1, SysTime2: TSystemTime;   TZinfo: TTimeZoneInformation; begin   GetTimeZoneInformation(TZinfo);     TZinfo.Bias := -TZinfo.Bias;   TZinfo.StandardBias := -TZinfo.StandardBias;   TZinfo.DaylightBias := -TZinfo.DaylightBias;   DateTimeToSystemTime(AValue, SysTime1);   SystemTimeToTzSpecificLocalTime(@TZinfo, SysTime1, SysTime2);    Result := SystemTimeToDateTime(SysTime2); end;

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function UTCToLocalTime(AValue: TDateTime): TDateTime; function LocalTimeToUTC(AValue: TDateTime): TDateTime;     function UTCToLocalTime(AValue: TDateTime): TDateTime;   var   SysTime1, SysTime2: TSystemTime;   TZinfo: TTimeZoneInformation; begin     GetTimeZoneInformation(TZinfo);   DateTimeToSystemTime(AValue, SysTime1);   SystemTimeToTzSpecificLocalTime(@TZinfo, SysTime1, SysTime2);   Result := SystemTimeToDateTime(SysTime2); end;   function LocalTimeToUTC(AValue: TDateTime): TDateTime;   var   SysTime1, SysTime2: TSystemTime;   TZinfo: TTimeZoneInformation; begin     GetTimeZoneInformation(TZinfo);     TZinfo.Bias := -TZinfo.Bias;   TZinfo.StandardBias := -TZinfo.StandardBias;   TZinfo.DaylightBias := -TZinfo.DaylightBias;     DateTimeToSystemTime(AValue, SysTime1);   SystemTimeToTzSpecificLocalTime(@TZinfo, SysTime1, SysTime2);    Result := SystemTimeToDateTime(SysTime2); end;