gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, TRUE, 0);
label = gtk_label_new ("Previous signal:");
gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, TRUE, 0);
calendar_data.prev_sig = gtk_label_new ("");
gtk_box_pack_start (GTK_BOX (hbox), calendar_data.prev_sig, FALSE, TRUE, 0);
gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, TRUE, 0);
label = gtk_label_new ("Previous signal:");
gtk_box_pack_start (GTK_BOX (hbox), label, FALSE, TRUE, 0);
calendar_data.prev_sig = gtk_label_new ("");
gtk_box_pack_start (GTK_BOX (hbox), calendar_data.prev_sig, FALSE, TRUE, 0);