private void TomorrowSubmitButton_Click(object sender, EventArgs e)
{
PersonalTask task = new PersonalTask(tomorrowTaskText.Text, DateHandler.GetDateFromToday(1));
AddTaskToListBox(task, TomorrowCheckedList);
}
private void YesterdaySubmit_Click(object sender, EventArgs e)
{
PersonalTask task = new PersonalTask(yesterdayText.Text, DateHandler.GetDateFromToday(-1));
AddTaskToListBox(task, YesterdayCheckedList);
}