diff --git a/arduino_timetable/timetable.py b/arduino_timetable/timetable.py
index 5ba7644..8465583 100644
--- a/arduino_timetable/timetable.py
+++ b/arduino_timetable/timetable.py
@@ -74,7 +74,7 @@ def parse_time_table(timetable, available_commands=None):
         # add a ScheduledCommand to the resulting list
         tc = ScheduledCommand(delta, raw_command, cmd)
         timed_commands.append(tc)
-    return timed_commands
+    return sorted(timed_commands, key=lambda tc: tc.delta)
 
 
 def parse_excel_file(path, available_commands=None):
@@ -122,7 +122,7 @@ def parse_excel_file(path, available_commands=None):
         # add a ScheduledCommand to the resulting list
         tc = ScheduledCommand(delta, raw_command, cmd)
         timed_commands.append(tc)
-    return timed_commands
+    return sorted(timed_commands, key=lambda tc: tc.delta)
 
 
 def parse_time_cell(excel_cell):