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MilliSecondOf

Function MilliSecondOf(const AValue: TDateTime): Word

Example​

procedure ScriptEvent(var Value: variant);
var
  InputValue: TDateTime;
begin
  InputValue := EncodeDateTime(2026, 7, 18, 9, 10, 11, 250);
  Value := MilliSecondOf(InputValue); // 250
end;

Usage​

MilliSecondOf returns the encoded millisecond-within-second component from 0 through 999.

Parameters

NameTypeDescription
AValueTDateTime, constEncoded date/time whose time-of-second fields are inspected.

Returns

A Word in the inclusive range 0 through 999.

Behaviour

  • The date component does not affect the result.
  • The value resets to zero at the next encoded second.
  • Decoding is sign-aware for valid pre-epoch TDateTime values, so the returned field position remains non-negative.
  • The routine extracts encoded wall-clock fields; it does not consult or convert a timezone.

Important usage notes

  • Velox decodes to millisecond resolution. Any finer binary fraction in a manually calculated TDateTime is subject to the runtime's timestamp rounding.
  • The result is not “milliseconds elapsed since” another instant and does not account for daylight-saving gaps, repeats or leap seconds.
  • Invalid or non-finite encoded input can raise during decoding rather than returning a sentinel.
  • Use an interval routine when the requirement is a duration; component indices wrap at their documented boundary.

Errors

Velox performs no validation or exception translation. Date/time decode exceptions propagate to the script.

Additional Technical Info​

MilliSecondOf returns the encoded millisecond-within-second component from 0 through 999. It is a position within the encoded second, not an elapsed-duration measurement between two values.

The example is fictional, deterministic and source-reviewed. It was not executed by the documentation workflow.

Implementation

The DateUtils import binds directly to Delphi 37.0 System.DateUtils.MilliSecondOf. It decodes the time fields and returns the millisecond component returned by DecodeTime.

Side effects

None.

Performance and concurrency

Constant-time component decoding and integer arithmetic with no external I/O or shared mutable state.

Remarks

This function is suitable for sorting, bucketing or formatting by encoded second position. Preserve the surrounding date/time fields when the value must identify an instant.

Related entries

External references

Created 2026-07-15