Date and time functions

[JotEmI]

I'm working on a new mod and found myself in need to do some date and time calculations (like comparing two dates, adding one date to another, etc.). As far as I know ScriptCore doesn't support TDateTime type or any of the date & time functions (except FormatDate()). So, before I roll up my sleeves and implement them on my own I'd like to ask if anyone already tried it and could share some code to speed up my work.

[Falcon`]

There's a good chance that you'll get whole set of date functions in 1.6.4, so perhaps just wait.

[JotEmI]

To be honest I'll probably finish my mod before you guys release 1.6.4 I only need to add specified number of hours and compare two dates so I'll just implement it myself for now.

[DorkeyDear]

I made a function a while ago which returns the number of seconds (or however much accuracy) since a reference by simply by converting multiple results of FormatDate into a number, multiplying most by a factor, and then adding them. I'll take a look for it real quick, but I doubt I'll be able to find it.

EDIT: I found not exactly what I'm looking for but I did make some timer related functions at one point. It is attached as time.pas with the following functions:

Code: [Select]

function time_Timer_New(): word;
procedure time_Timer_Delete(const Timer: word);
procedure time_Timer_Start(const Timer: word);
procedure time_Timer_Pause(const Timer: word);
function time_Timer_GetTime(const Timer: word): extended;
function time_Span_FromDays(const Time: extended): int64;
function time_Span_FromHours(const Time: extended): int64;
function time_Span_FromMinutes(const Time: extended): int64;
function time_Span_FromSeconds(const Time: extended): int64;
function time_Span_FromMilliSeconds(const Time: extended): int64;
function time_Span_FromMicroSeconds(const Time: extended): int64;
function time_Span_FromPart(const Time: extended; const Part: byte): int64;
function time_Span_GetTotalDays(const Time: int64): extended;
function time_Span_GetTotalHours(const Time: int64): extended;
function time_Span_GetTotalMinutes(const Time: int64): extended;
function time_Span_GetTotalSeconds(const Time: int64): extended;
function time_Span_GetTotalMilliSeconds(const Time: int64): extended;
function time_Span_GetTotalMicroSeconds(const Time: int64): extended;
function time_Span_GetTotalPart(const Time: int64; const Part: byte): extended;
function time_Span_GetDays(const Time: int64): int64;
function time_Span_GetHours(const Time: int64): int64;
function time_Span_GetMinutes(const Time: int64): int64;
function time_Span_GetSeconds(const Time: int64): int64;
function time_Span_GetMilliSeconds(const Time: int64): int64;
function time_Span_GetMicroSeconds(const Time: int64): int64;
function time_Span_GetPart(const Time: int64; const Part: byte): int64;
function time_Span_LabelPart(const Part: byte): string;
function time_Span_ToStringOpt(Time: int64; const LowerPartBound, UpperPartBound: byte): string;
function time_Span_ToString(const Time: int64): string;
EDIT2: I found what I was origonally looking for. Here it is:

Code: [Select]

function MonthDays(const Month: byte): byte;
begin
  case (Month) of
    1, 3, 5, 7, 9, 11: Result := 31;
    4, 6, 8, 10, 12: Result := 30;
    2: Result := 28;
  end;
end;

function GetTime: cardinal;
begin
  Result := 31536000000 * (StrtoInt(FormatDate('y')) - 2008) + 86400000 * MonthDays(StrtoInt(FormatDate('m'))) * StrtoInt(FormatDate('m')) + 86400000 * StrtoInt(FormatDate('d')) + 3600000 * StrtoInt(FormatDate('h')) + 60000 * StrtoInt(FormatDate('n')) + 1000 * StrtoInt(FormatDate('s')) + StrtoInt(FormatDate('zzz'));
end;

[JotEmI]

Thx, I'll be sure to look into it.

EDIT:
After all I've decided to create a structure similar to the DateTime class in .NET. I've used the standard Julian Day Number to calculate time difference in days, hours, minutes and seconds.

Snippets:

Code: [Select]

type TDateTime=record
Year: integer;
Month: integer;
Day: integer;
Hour: integer;
Minute: integer;
Second: integer;
end;

...

//JDN() - returns Julian Day Number from date
function JDN(date: TDateTime): integer;
begin
Result:=(367*date.Year)-7*(date.Year+(date.Month+9)/12)/4-3*((date.Year+(date.Month-9)/7)/100+1)/4+275*date.Month/9+date.Day+1721029;
end;

//DateDiff() - returns difference between two dates
//Date part:
//year or y - difference of years
//month or m - difference of months
//day or d - difference of days
//hour or h - difference of hours
//minute or m - difference of minutes
//second or s - difference of seconds
function DateDiff(datepart: string; date1,date2: TDateTime): integer;
var
r,days,hours,minutes: integer;
d1,d2: TDateTime;
begin
r:=0;
d1:=date1;
d2:=date2;
if(datepart='year')or(datepart='y')then r:=d2.Year-d1.Year
else if(datepart='month')or(datepart='M')then r:=((d2.Year-d1.Year)*12)+(d2.Month-d1.Month)
else if(datepart='day')or(datepart='d')then r:=JDN(d2)-JDN(d1)
else if(datepart='hour')or(datepart='h')then r:=(JDN(d2)-JDN(d1))*24+(d2.Hour-d1.Hour)
else if(datepart='minute')or(datepart='m')then
begin
days:=JDN(d2)-JDN(d1);
hours:=d2.Hour-d1.Hour;
r:=(days*1440)+(hours*60)+(d2.Minute-d1.Minute);
end
else if(datepart='second')or(datepart='s')then
begin
days:=JDN(d2)-JDN(d1);
hours:=d2.Hour-d1.Hour;
minutes:=d2.Minute-d1.Minute;
r:=(days*86400)+(hours*3600)+(minutes*60)+(d2.Second-d1.Second);
end;
Result:=r;
end;

Complete code with comments is attached below if anyone would like to use it.
Example of usage:

Code: [Select]

var
d1,d2: TDateTime;

d1:=ParseDate(FormatDate('yyyy-MM-dd hh:mm:ss'));
WriteLn(DateToStr(d1,'MM/dd/yyyy hh:mm:ss'));

d2:=DateAdd('day',10,d1);
WriteLn(inttostr(DateDiff('day',d1,d2)));

if(CompareDates(d1,d2)=1)then WriteLn('d1>d2')
else if(CompareDates(d1,d2)=-1)then WriteLn('d1<d2');