Define a constructor for form2 accepting the date which will be the upper bound of the data to display. Use this date to populate form's data.
In form1, in the button's click handler, use form2's constructor to pass the desired date.
public class Form2 : Form
{
private DateTime UpperBound { get; set; }
public Form2(DateTime date)
{
UpperBound = date;
Build();
}
private void Build()
{
}
}
public class Form1 : Form
{
private void button_Click(object sender, EventArgs e)
{
Form2 form = new Form2(DateTime.Today);
form.Show();
}
}