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MinutesBetween

Function MinutesBetween(const ANow, AThen: TDateTime): Int64

Example​

procedure ScriptEvent(var Value: variant);
var
  FirstValue, SecondValue: TDateTime;
begin
  FirstValue := EncodeDateTime(2026, 7, 18, 9, 0, 0, 0);
  SecondValue := EncodeDateTime(2026, 7, 18, 9, 1, 30, 0);
  Value := MinutesBetween(FirstValue, SecondValue); // 1
end;

Usage​

MinutesBetween returns the absolute number of complete minutes between two timestamp-normalised values.

Parameters

NameTypeDescription
ANowTDateTime, constFirst encoded date/time. It need not be current or later.
AThenTDateTime, constSecond encoded date/time. Argument order does not affect the result.

Returns

The non-negative count of complete minutes as an Int64. Equal values and intervals shorter than one minute return zero.

Behaviour

  • Argument order is ignored because the difference is absolute.
  • Partial minutes are truncated, not rounded. A span of 1 minute 59.999 seconds returns 1.
  • Timestamp normalisation supports valid timed pre-epoch and cross-epoch values correctly at millisecond resolution.
  • No timezone or daylight-saving conversion is applied.

Important usage notes

  • The function cannot indicate which input is later.
  • Sub-millisecond fractions are rounded during timestamp conversion before integer division.
  • The names ANow and AThen are conventional and do not impose ordering.
  • Values encoded under different timezone conventions must be normalised by the caller before comparison.

Usage notes

Use MinuteSpan when a fractional-minute result is required and its raw pre-epoch limitation is acceptable.

Additional Technical Info​

MinutesBetween returns the absolute number of complete 60,000-millisecond periods between two encoded date/time values. The inputs are normalised through Delphi timestamps before subtraction, and any partial minute is discarded.

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.MinutesBetween. Each input is converted to a chronological Int64 millisecond value through DateTimeToTimeStamp; the absolute difference is then divided by 60,000 using integer division.

Side effects

None.

Errors

Invalid or non-finite input can raise during timestamp conversion. Velox does not catch or translate the exception.

Performance and concurrency

Constant-time timestamp conversion and 64-bit integer arithmetic with no shared mutable state.

Related entries

External references

Created 2026-07-15