diff --git a/src/data.cpp b/src/data.cpp
index 7a115b4e..43d40041 100644
--- a/src/data.cpp
+++ b/src/data.cpp
@@ -656,3 +656,14 @@ Interval getLatestInterval (Database& database)
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+Range getFullDay (const Datetime& day)
+{
+  int y;
+  int m;
+  int d;
+  day.toYMD (y, m, d);
+  return Range (Datetime (y, m, d, 0, 0, 0),
+                Datetime (y, m, d, 23, 59, 59));
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/src/timew.h b/src/timew.h
index 930cab1f..c5adf960 100644
--- a/src/timew.h
+++ b/src/timew.h
@@ -54,6 +54,7 @@ Interval                clip                (const Interval&, const Range&);
 std::vector <Interval>  getTrackedIntervals (Database&, const Rules&, Interval&);
 std::vector <Range>     getUntrackedRanges  (const Rules&);
 Interval                getLatestInterval   (Database&);
+Range                   getFullDay          (const Datetime&);
 
 // init.cpp
 bool lightweightVersionCheck (int, const char**);