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VarToDateTime

Function VarToDateTime(const V : Variant) : TDateTime

Example​

procedure ScriptEvent(var Value: variant);
var
  Candidate: Variant;
begin
  Candidate := EncodeDate(2026, 7, 19);
  Value := VarToDateTime(Candidate);
end;

Usage​

VarToDateTime converts a Variant to a Velox TDateTime using type-specific and host-locale rules.

Parameters and result

ItemTypeDescription
VVariant (const)Date/time, numeric, textual, Boolean, interface or custom Variant to convert.
ResultTDateTimeVelox date/time serial: the integral part represents days relative to the Velox epoch and the fractional part represents time of day. No time-zone identity is carried.

Errors

Unsupported types, invalid text, strict Null conversion, out-of-range Automation dates and failed custom/interface conversions raise EVariantError items. There is no fallback parameter and no Boolean success result.

Additional Technical Info​

VarToDateTime converts V to a Delphi TDateTime value. The conversion path depends on the Variant's stored type: date Variants are returned directly, integers are treated as Delphi date serials, and text or other Automation types use locale-sensitive conversion.

The example is fictional and source-reviewed only. It avoids a locale-dependent date literal.

Implementation

The Velox wrapper delegates to System.Variants.VarToDateTime, which calls Delphi's internal Variant-to-date conversion.

  • varDate returns its stored TDateTime directly.
  • Empty/varEmpty returns 0.
  • Small and ordinary integer types are used as numeric day serials. Int64/UInt64, floating and Currency paths use Delphi/Automation conversion where needed.
  • Text is first passed to the operating-system Variant date parser with the user-default locale. If that reports a type mismatch, Delphi tries its current date parser and then its current floating parser.
  • Interface, custom and by-reference Variant types use their supported Delphi Variant conversion path.

Edge cases and quirks

  • 0 is a valid TDateTime value representing the Delphi epoch, not a conversion-failure sentinel.
  • Null normally raises under Delphi's default strict Null-conversion policy. If host code disables NullStrictConvert, Null converts to 0. Test with VarIsNull when this distinction matters.
  • Boolean values are converted numerically. Delphi WordBool true is normally -1, so Boolean-to-date conversion is legal but rarely meaningful.
  • Numeric input is a serial value, not a Unix timestamp, YYYYMMDD number or duration. Convert those representations explicitly.
  • Text acceptance and day/month order depend on the Velox process host's Windows user locale and Delphi format settings. A string accepted on one server may be rejected or interpreted differently on another.
  • Numeric text can be accepted by the final floating fallback and treated as a date serial.
  • TDateTime is a floating representation with no time-zone or daylight-saving metadata. This function does not parse or normalise an offset into a zoned instant.

Performance and concurrency

Direct date and integer cases are constant-time. Text/Automation paths allocate temporary text and call locale-aware conversion services. The wrapper mutates no state, but output can depend on process-wide locale/format settings; changing those settings concurrently is not a safe way to control parsing.

Related entries

  • VarAsType with varDate returns a date-typed Variant rather than a TDateTime result.
  • VarIsNull lets a script define its own Null rule before conversion.
  • Date/time conversion functions provide alternatives when the input format is known and should not depend on Variant coercion.

External references

Created 2026-07-15