How to parse UTC date? [duplicate]

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How do I convert an ISO 8601 string to a Delphi TDate? (7 answers)

Closed 8 years ago.

I need to parse UTC date using Delphi 6:

2013-12-24T11:05:01.000+09:00

In Delphi 7 I managed to do this with the following code:

1. Using TXsDateTime:

   var
    utcTime : TXsDateTime;
    localTime : TDateTime;
    temp : string;
   begin
    temp := '2013-12-24T00:00:00.000-02:00';
    utcTime.XSToNative(temp);
    localTime := utcTime.AsUTCDateTime; // get time in +00:00 timezone
    localTime := IncHour(localTime, 9); // het time local timezone
    //...
   end;
   

2. Using StrToDateTime overload with TFormatSettings:

   var
     localTime : TDateTime;
     temp, datetimePart : string;
     formatSettings : TFormatSettings;
   begin
    temp := '2013-12-24T00:00:00.000+01:00';
    //init format settings
    GetLocaleFormatSettings(LOCALE_SYSTEM_DEFAULT, formatSettings);
    formatSettings.DateSeparator := '-';
    formatSettings.ShortDateFormat := 'yyyy-MM-dd';
    //parse datetime
    datetimePart := StringReplace(copy(temp,1,Length(temp)-10),'T',' ',[]);
    localTime := StrToDateTime(datetimePart, formatSettings);
    //get datetime in +00:00 timezone
    localTime := IncHour(localTime, -1*strtoint(copy(temp,Length(temp)-5,3)));
    localTime := IncMinute(localTime, -1*strtoint(copy(temp,Length(temp)-1,2)));
    //get datetime in local timezone
    localTime := IncHour(localTime , 9);
    //...
   end;
   

But in Delphi 6:

1. I cannot even call XSToNative, as it throws EConvertError misplacing month and day parts of the date; and also TXsDateTime does not contain definition for AsUTCDateTime...
2. SysUtils does not contain definition for TFormatSettings and consequently the overload of StrToDateTime I use is unavailable.

Is there anything I am missing, or what else can I use to parse this format in Delphi 6?

Answer 1

In the end I used EncodeDateTime function:

var
 time1, time2 : TDateTime;
 year,month,day,hour,minute,second,mlsecond, hourOffset, minOffset : integer;
 temp :string;
begin
 temp := '2013-12-24T00:00:00.000-09:30';
 //parse separate parts of the datetime
 year := strtoint(copy(temp,1,4));
 month := strtoint(copy(temp,6,2));
 day := strtoint(copy(temp,9,2));
 hour := strtoint(copy(temp,12,2));
 minute := strtoint(copy(temp,15,2));
 second := strtoint(copy(temp,18,2));
 mlsecond := strtoint(copy(temp,21,3));
 hourOffset := strtoint(copy(temp,25,2));
 minOffset := strtoint(copy(temp,28,2));
 //adjust timezone offset sign
 if(temp[24]='+')then
 begin
  hourOffset := -1 * hourOffset;
  minOffset := -1 * minOffset;
 end;
 //get time in the +00:00 timezone
 time1 := EncodeDateTime(year,month,day,hour,minute,second,mlsecond);
 time1 := IncHour(time1, hourOffset);
 time1 := IncMinute(time1, minOffset);
 //get time in local timezone
 time2 := IncHour(time1, 9);
 //...
end;