diff --git a/src/RideFile.cpp b/src/RideFile.cpp
index fe8b40bf2..97291ffd0 100644
--- a/src/RideFile.cpp
+++ b/src/RideFile.cpp
@@ -21,8 +21,51 @@
 #include "Settings.h"
 #include "Units.h"
 #include <QtXml/QtXml>
+#include <algorithm> // for std::lower_bound
 #include <assert.h>
 
+#define mark() \
+{ \
+    addInterval(start, previous->secs + recIntSecs_, \
+                QString("%1").arg(interval)); \
+    ++interval; \
+    start = point->secs; \
+}
+
+void
+RideFile::fillInIntervals()
+{
+    if (dataPoints_.empty())
+        return;
+    intervals_.clear();
+    double start = 0.0;
+    int interval = dataPoints().first()->interval;
+    const RideFilePoint *point, *previous;
+    foreach (point, dataPoints()) {
+        if (point->interval != interval)
+            mark();
+        previous = point;
+    }
+    mark();
+}
+
+struct ComparePoints {
+    bool operator()(const RideFilePoint *p1, const RideFilePoint *p2) {
+        return p1->secs < p2->secs;
+    }
+};
+
+int
+RideFile::intervalBegin(const RideFileInterval &interval) const
+{
+    RideFilePoint p;
+    p.secs = interval.start;
+    QVector<RideFilePoint*>::const_iterator i = std::lower_bound(
+        dataPoints_.begin(), dataPoints_.end(), &p, ComparePoints());
+    assert(i != dataPoints_.end());
+    return i - dataPoints_.begin();
+}
+
 void RideFile::writeAsCsv(QFile &file, bool bIsMetric) const
 {
 
diff --git a/src/RideFile.h b/src/RideFile.h
index 478475660..312f9c135 100644
--- a/src/RideFile.h
+++ b/src/RideFile.h
@@ -63,6 +63,15 @@ struct RideFileDataPresent
         kph(false), nm(false), watts(false), alt(false), interval(false) {}
 };
 
+struct RideFileInterval
+{
+    double start, stop;
+    QString name;
+    RideFileInterval() : start(0.0), stop(0.0) {}
+    RideFileInterval(double start, double stop, QString name) :
+        start(start), stop(stop), name(name) {}
+};
+
 class RideFile
 {
     private:
@@ -72,6 +81,7 @@ class RideFile
         QVector<RideFilePoint*> dataPoints_;
         RideFileDataPresent dataPresent;
         QString deviceType_;
+        QList<RideFileInterval> intervals_;
 
     public:
 
@@ -99,6 +109,13 @@ class RideFile
                          double kph, double nm, double watts, double alt,
                          int interval, double bs=0.0);
 
+        const QList<RideFileInterval> &intervals() const { return intervals_; }
+        void addInterval(double start, double stop, const QString &name) {
+            intervals_.append(RideFileInterval(start, stop, name));
+        }
+        void fillInIntervals();
+        int intervalBegin(const RideFileInterval &interval) const;
+
         void writeAsCsv(QFile &file, bool bIsMetric) const;
 
         void resetDataPresent();