diff --git a/src/WatchFeatures/RTC.cpp b/src/WatchFeatures/RTC.cpp
index fb40f85..cd0aef3 100644
--- a/src/WatchFeatures/RTC.cpp
+++ b/src/WatchFeatures/RTC.cpp
@@ -102,6 +102,8 @@ void WatchFeatures::RTC::OffsetTime(tmElements_t & tm, int offsetInSeconds)
   tm.Hour = hour;
   tm.Minute = minute;
   tm.Second = second;
+  time_t t = makeTime(tm); // make and break to calculate tm.Wday
+  breakTime(t, tm);
 }
 
 // TODO: implement more advanced wakeup logic, i.e. > 255 seconds that are not a multiple of 60