Skip to main content

InvalidDateTimeError

Procedure InvalidDateTimeError(const AYear, AMonth, ADay, AHour, AMinute, ASecond, AMilliSecond: Word; const ABaseDate: TDateTime)

Example​

procedure ScriptEvent(var Value: variant);
begin
  try
    InvalidDateTimeError(2026, 2, 30, 9, 0, 0, 0, 0);
  except
    Value := 'Invalid date and time fields were rejected';
  end;
end;

Usage​

InvalidDateTimeError raises a locale-formatted DateUtils invalid date/time error after resolving leave-as-is fields against a base value.

Parameters

NameTypeDescription
AYearWord, constYear to report, or the leave-as-is sentinel described below.
AMonthWord, constMonth to report, or the leave-as-is sentinel.
ADayWord, constDay to report, or the leave-as-is sentinel.
AHourWord, constHour to report, or the leave-as-is sentinel.
AMinuteWord, constMinute to report, or the leave-as-is sentinel.
ASecondWord, constSecond to report, or the leave-as-is sentinel.
AMilliSecondWord, constMillisecond to report, or the leave-as-is sentinel.
ABaseDateTDateTime, constBase value used to resolve leave-as-is fields. Zero requests the missing-field marker instead.

Behaviour

  • The procedure always raises; it does not determine whether the supplied fields form a valid value.
  • Velox uses 65535 to mean "leave this field as is". Pass that literal only when this documented sentinel is intended.
  • When a field is 65535 and ABaseDate is non-zero, the corresponding decoded base component is inserted into the message.
  • When a field is 65535 and ABaseDate is zero, DateUtils inserts its missing-date/time-field text instead of a numeric component.
  • Other field values are formatted as supplied, even when they happen to be valid.

Usage notes

For normal input handling, use IsValidDateTime and produce a message appropriate to the business rule. This always-raising helper is primarily a low-level compatibility entry.

Additional Technical Info​

InvalidDateTimeError deliberately constructs and raises DateUtils' general invalid date/time conversion error. It can resolve special leave-as-is field values from a base date/time before formatting the message; it does not validate the fields itself.

The example is fictional and source-reviewed. It catches the expected exception and was not executed by the documentation workflow.

Implementation

The DateUtils import binds directly to Delphi 37.0 System.DateUtils.InvalidDateTimeError. The routine decodes ABaseDate, resolves every field equal to DateUtils' RecodeLeaveFieldAsIs sentinel, formats the date/time using the process-wide FormatSettings separators and immediately raises EConvertError.

Edge cases and quirks

  • ABaseDate = 0 is treated as “no base date”, even though zero is also Delphi's valid epoch value, 30 December 1899 at midnight. It therefore cannot be used as an actual base for sentinel resolution.
  • The displayed date separator, time separator and decimal separator come from global host FormatSettings. Message punctuation can differ between machines or change while process-wide locale settings are changed.
  • The Word declaration excludes negative fields but accepts values far beyond normal date/time ranges.
  • This helper exposes a Delphi recoding implementation detail to scripts. Use it only when the standard DateUtils exception is specifically required.

Side effects

Control leaves by exception. Message formatting reads process-wide locale settings but performs no external I/O.

Errors

The intended result is an EConvertError. Decoding an unsuitable base value can itself raise before the final resource-formatted exception is constructed. Human-readable text is not a stable machine contract.

Performance and concurrency

Constant-time decoding and formatting. Concurrent mutation of global FormatSettings can affect the message and should be avoided by the hosting application.

Related entries

External references

Created 2026-07-15