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EndOfTheMonth

Function EndOfTheMonth(const AValue: TDateTime): TDateTime

Example​

procedure ScriptEvent(var Value: variant);
begin
  Value := EndOfTheMonth(EncodeDate(2028, 2, 10)); // 29 February, 23:59:59.999
end;

Usage​

EndOfTheMonth returns the final millisecond of the calendar month containing a supplied TDateTime value.

Parameters

NameTypeDescription
AValueTDateTime, constSupported date/time whose containing calendar month is selected; its day and time do not otherwise affect the result.

Returns

The final valid calendar day of AValue's month at 23:59:59.999.

Important usage notes

  • The input's original day and clock fields are discarded.
  • The month boundary is calendar-based and timezone-neutral.
  • The output is millisecond-resolution; use an exclusive next-month start for robust range predicates over higher-precision storage.
  • Unsupported raw values can decode to invalid zero fields and fail in the subsequent month-length path.

Errors

Invalid or unsupported raw values propagate RTL conversion/range failures. Valid TDateTime dates do not raise.

Additional Technical Info​

EndOfTheMonth derives the calendar year and month from AValue, selects that month's final valid date and returns its final millisecond.

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

Implementation

The DateUtils import binds to Delphi 37.0 System.DateUtils.EndOfTheMonth. It decodes year/month/day, reads the month's length (including leap-year February), encodes that final day and delegates to EndOfTheDay.

Side effects

None.

Performance and concurrency

Constant-time field extraction, table lookup and encoding with read-only shared tables.

Related entries

External references

Created 2026-07-15