diff --git a/PyTado/const.py b/PyTado/const.py
index c55fb2c..7ed43a3 100644
--- a/PyTado/const.py
+++ b/PyTado/const.py
@@ -23,9 +23,14 @@
 CONST_FAN_HIGH = "HIGH"
 
 # When we change the temperature setting, we need an overlay mode
-CONST_OVERLAY_TADO_MODE = "NEXT_TIME_BLOCK"  # wait until tado changes the mode automatic
+# The tado API distinguishes between type and typeSkillBasedApp
+# There are 3 main types: TADO_MODE, MANUAL, and TIMER
+# The TIMER Type can be used with either typeSkillBasedApp TIMER to wait an also provided time or with NEXT_TIME_BLOCK which automatically sets the time until the next time block for the zone begins
+CONST_OVERLAY_TADO_MODE = "TADO_MODE"  # wait until tado changes the mode automatic (e.g., by next time block or change in home state)
 CONST_OVERLAY_MANUAL = "MANUAL"  # the user has change the temperature or mode manually
 CONST_OVERLAY_TIMER = "TIMER"  # the temperature will be reset after a timespan
+CONST_OVERLAY_NEXT_TIME_BLOCK = "NEXT_TIME_BLOCK"  # set overlay until start of the next time block (ignoring intermediate home state changes)
+
 
 # Heat always comes first since we get the
 # min and max tempatures for the zone from