VB.NET

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.

VB.NET

Dim success As Boolean = False

' This example demonstrates how to set a custom last-modified date/time
' that will be embedded in a Gzip file.

Dim gzip As New Chilkat.Gzip
Dim dt As New Chilkat.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:
success = gzip.SetDt(dt)
If (success = False) Then
    Debug.WriteLine(gzip.LastErrorText)
    Exit Sub
End If


' Compress a string so the custom date/time is embedded in the .gz:
Dim inputStr As String = "Example text for Gzip compression."
success = gzip.CompressStringToFile(inputStr,"utf-8","output.gz")
If (success = False) Then
    Debug.WriteLine(gzip.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Gzip file created with custom last-modified date.")