In Delphi: How do I round a TDateTime to closest second, minute, five-minute etc?

Question

Does there exist a routine in Delphi that rounds a TDateTime value to the closest second, closest hour, closest 5-minute, closest half hour etc?

UPDATE:

Gab

Answer 1

If anyone reads this far down in the post then here's another thought. As z666zz666z said, it doesn't have to be complicated. TDateTime in Delphi is a double precision floating point number with the integer portion representing the day. If the rounding value is passed as the number of 'periods' in the day then the rounding function would simply be: Round(dt * RoundingValue) / RoundingValue. The method would be:

procedure RoundTo(var dt: TDateTime; RoundingValue:integer);
    begin
    if RoundingValue > 0 then
        dt := Round(dt * RoundingValue) / RoundingValue;
    end;

Examples:

RoundTo(targetDateTime, SecsPerDay); // round to the nearest second
RoundTo(targetDateTime, SecsPerDay div 10); // round to the nearest 10 seconds
RoundTo(targetDateTime, MinsPerDay); // round to the nearest minute
RoundTo(targetDateTime, MinsPerDay div 5); // round to the nearest five minutes
RoundTo(targetDateTime, HoursPerDay); // round to the nearest hour

It even caters to sub second rounding:

RoundTo(targetDateTime, SecsPerDay * 10); // round to the nearest 1/10 second