How can I get the value of my form 2 to form 1

Exactly how depends on the "relationship" between the two forms.
Have a look at these, one of them will fit your circumstances.
The form that creates an instance of another:

Dim mf As MyForm = New MyForm()
mf.Show()

Is the "parent", the other form is the "child".
(This doesn't imply any formal MDI relationship)

Transferring information between two forms, Part 1: Parent to Child[^]
Transferring information between two forms, Part 2: Child to Parent[^]
Transferring information between two forms, Part 3: Child to Child[^]

The code is in C#, but it's pretty simple - and if you really can't work it out then online converters like Code Converter C# to VB and VB to C# – Telerik[^] do a pretty good job of converting between the two languages.

I am going to assume from reading this, that you have created both forms and control them with .show and .hide. Try this simple solution. Reverse your show and hide on form 2 and make the assignment in-between. It appears your assignment is also reversed.
to get form2.textbox1 to form1, should be

Form1.TextBox1.Text = TextBox1.Text

Yours form2:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
       Dim newdate As String
       newdate = TextBox1.Text
       MessageBox.Show("Date will be applied " & newdate & ".txt")
       Me.Hide()
       Form1.Show()

Try: form2

<pre>Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
       Dim newdate As String
       newdate = TextBox1.Text
       MessageBox.Show("Date will be applied " & newdate & ".txt")
       Form1.Show()
       Form1.TextBox1.Text = TextBox1.Text
       Me.Hide()

I agree with the comment on the issue with this. This was based on the supplied code. A better way would be to declare a public variable in a module. On the form2 closing event set the variable to the textbox value. Then on the form1 load event, set the textbox value to the variable.