diff --git a/NightLight.Core/PartsOfDay.fs b/NightLight.Core/PartsOfDay.fs
index f7b47d2..f50c002 100644
--- a/NightLight.Core/PartsOfDay.fs
+++ b/NightLight.Core/PartsOfDay.fs
@@ -8,5 +8,9 @@ type PartOfDay =
 
 let getPartOfDay (dateTime: DateTime) =
     match dateTime with
-    | _ when dateTime.TimeOfDay >= TimeSpan.FromHours 4.75 && dateTime.TimeOfDay < TimeSpan.FromHours 20.5 -> Day
+    | _ when
+        dateTime.TimeOfDay >= TimeSpan.FromHours 5.5
+        && dateTime.TimeOfDay < TimeSpan.FromHours 20.5
+        ->
+        Day
     | _ -> Night
diff --git a/README.md b/README.md
index 1446cf8..b70f026 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 This is an F# program that turns all the lights in our apartment
 
 * _red_ at 8.30pm in the evening, and
-* _white_/_yellow_ (depending on the room) at 4.45am in the morning.
+* _white_/_yellow_ (depending on the room) at 5.30am in the morning.
 
 `NightLight.Core` is the functional core, and `NightLight` is the imperative shell.