Dart

Set a Custom Last-Modified Date in a Gzip File

See more Gzip Examples

This example demonstrates how to use the SetDt method to specify a custom last-modified date and time that will be embedded in a Gzip file.

A CkDateTime object is first initialized with a specific date/time using an RFC 822 formatted string. This date/time is then applied to the Gzip object using SetDt.

When a compression method is called (such as CompressStringToFile), the specified date/time is included in the Gzip metadata. This allows the resulting .gz file to carry a meaningful timestamp rather than using the current system time.

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // This example demonstrates how to set a custom last-modified date/time
  // that will be embedded in a Gzip file.

  final gzip = CkGzip();
  final dt = CkDateTime();

  // Set the date/time using a timestamp format (ISO 8601 style):
  dt.setFromTimestamp('2025-11-15T12:45:26-05:00');

  // Apply the date/time to the Gzip object:
  try {
    gzip.setDt(dt);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Compress a string so the custom date/time is embedded in the .gz:
  final inputStr = 'Example text for Gzip compression.';
  try {
    gzip.compressStringToFile(inputStr, 'utf-8', 'output.gz');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Gzip file created with custom last-modified date.');
}