diff --git a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/converter/FitbitIntradayHeartRateAvroConverter.java b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/converter/FitbitIntradayHeartRateAvroConverter.java
index 89bc4cf1..92fb75e5 100644
--- a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/converter/FitbitIntradayHeartRateAvroConverter.java
+++ b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/converter/FitbitIntradayHeartRateAvroConverter.java
@@ -64,12 +64,18 @@ protected Stream<TopicData> processRecords(
 
     // Used as the date to convert the local times in the dataset to absolute times.
     ZonedDateTime startDate = request.getDateRange().start();
+    Instant rangeStart = startDate.toInstant();
+    Instant rangeEnd = request.getDateRange().end().toInstant();
 
     return iterableToStream(dataset)
         .map(tryOrNull(activity -> {
           Instant time = startDate.with(LocalTime.parse(activity.get("time").asText()))
               .toInstant();
 
+          if (time.isBefore(rangeStart) || !time.isBefore(rangeEnd)) {
+            return null;
+          }
+
           FitbitIntradayHeartRate heartRate = new FitbitIntradayHeartRate(
               time.toEpochMilli() / 1000d,
               timeReceived,
diff --git a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/route/FitbitIntradayHeartRateRoute.java b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/route/FitbitIntradayHeartRateRoute.java
index f7f06644..f7e80044 100644
--- a/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/route/FitbitIntradayHeartRateRoute.java
+++ b/kafka-connect-fitbit-source/src/main/java/org/radarbase/connect/rest/fitbit/route/FitbitIntradayHeartRateRoute.java
@@ -17,7 +17,7 @@
 
 package org.radarbase.connect.rest.fitbit.route;
 
-import static java.time.format.DateTimeFormatter.ISO_LOCAL_TIME;
+import static java.time.temporal.ChronoUnit.DAYS;
 import static java.time.temporal.ChronoUnit.SECONDS;
 
 import io.confluent.connect.avro.AvroData;
@@ -46,8 +46,10 @@ protected Stream<FitbitRestRequest> createRequests(User user) {
     return startDateGenerator(getOffset(user).plus(ONE_SECOND).truncatedTo(SECONDS))
         .map(dateRange -> newRequest(user, dateRange,
             user.getExternalUserId(), DATE_FORMAT.format(dateRange.start()),
-            ISO_LOCAL_TIME.format(dateRange.start()),
-            ISO_LOCAL_TIME.format(dateRange.end().truncatedTo(SECONDS))));
+            // Always request full day boundaries
+            TIME_FORMAT.format(dateRange.start().truncatedTo(DAYS).truncatedTo(SECONDS)),
+            TIME_FORMAT.format(dateRange.start().truncatedTo(DAYS).plusDays(1).minusNanos(1)
+                .truncatedTo(SECONDS))));
   }
 
   @Override