diff --git a/soft/thermostat/src/mainwindow.cpp b/soft/thermostat/src/mainwindow.cpp
index 30ca7d7..4fd1942 100644
--- a/soft/thermostat/src/mainwindow.cpp
+++ b/soft/thermostat/src/mainwindow.cpp
@@ -130,10 +130,15 @@ double MainWindow::get_target_temperature(int room_idx)
 		goto out;
 	}
 
+	/*
+	 * dayOfWeek() returns 1 for monday, 7 for sunday.
+	 * so dow <<= 1 gives 0 for monday, 6 for sunday.
+	 * And (1 << dow) gives the day of week as a bit field
+	 */
 	dow <<= 1;
 	for (int i = 0; i < r->progs.count(); i++) {
 		p = &(r->progs.at(i));
-		if (dow & p->DoW) {
+		if ((1 << dow) & p->DoW) {
 			if (p->start_time == p->end_time) {
 				continue;
 			}