TryEncodeTime

function TryEncodeTime(Hour, Min, Sec, MSec: Word;
  var Time: TDateTime): Boolean;

Example

procedure ScriptEvent(var Value: variant);
var
  EncodedTime: TDateTime;
begin
  if TryEncodeTime(14, 30, 45, 125, EncodedTime) then
    Value := EncodedTime;
end;

Usage

TryEncodeTime tries to encode hour, minute, second and millisecond fields as a time-of-day fraction.

Parameters

Name	Type	Description
Hour	Word	Hour 0..23.
Min	Word	Minute 0..59.
Sec	Word	Second 0..59; leap-second value 60 is invalid.
MSec	Word	Millisecond 0..999.
Time	TDateTime, var	Receives the encoded fraction on success.

Errors

Any error encountered while encoding returns False instead of being raised to the script.

Additional Technical Info

TryEncodeTime exposes a Velox/PascalScript adapter that attempts to encode four clock fields as a time-only TDateTime fraction. It catches encoding exceptions and returns a Boolean result.

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

Returns

True when System.SysUtils.EncodeTime succeeds; otherwise False.

Implementation

The modified PascalScript runtime registers its own adapter rather than binding System.SysUtils.TryEncodeTime directly. Inside a broad try/except, it assigns Time := EncodeTime(Hour, Min, Sec, MSec) and returns True; any exception is swallowed and converted to False.

Edge cases and quirks

• Installed Delphi 37.0 EncodeTime rejects hour 24. Exact 24:00:00.000 therefore returns False, despite current DocWiki text saying the upstream try routine accepts that boundary.
• On failure, the assignment never completes and the script's var Time retains its previous numeric value. Consume it only after a True result.
• The adapter catches every exception, not just the expected EConvertError; diagnostic detail is discarded.
• There is no date or timezone information in the returned fraction.
• Precision is one millisecond.

Side effects

Writes Time on success only. No I/O or shared state.

Performance and concurrency

Constant-time arithmetic and exception handling with no shared mutable state.

Related entries

• EncodeTime propagates the conversion exception.
• TryEncodeDateTime calls Delphi's direct try encoder rather than this PascalScript adapter.
• DecodeTime decomposes an encoded value.

External references

• Embarcadero System.SysUtils.TryEncodeTime - the page's hour-24 claim differs from the installed EncodeTime terminal used by Velox's adapter.
• Free Pascal TryEncodeTime

Created 2026-07-15