diff --git a/Ical.Net/Evaluation/RecurrencePatternEvaluator.cs b/Ical.Net/Evaluation/RecurrencePatternEvaluator.cs
index 937c9455a..f97f0bd50 100644
--- a/Ical.Net/Evaluation/RecurrencePatternEvaluator.cs
+++ b/Ical.Net/Evaluation/RecurrencePatternEvaluator.cs
@@ -69,20 +69,37 @@ private RecurrencePattern ProcessRecurrencePattern(IDateTime referenceDate)
                 r.Until = DateUtil.MatchTimeZone(referenceDate, new CalDateTime(r.Until, referenceDate.TzId)).Value;
             }
 
-            if (r.Frequency > FrequencyType.Secondly && r.BySecond.Count == 0 && referenceDate.HasTime
-                /* NOTE: Fixes a bug where all-day events have BySecond/ByMinute/ByHour added incorrectly */)
+            if (referenceDate.HasTime)
             {
-                r.BySecond.Add(referenceDate.Second);
-            }
-            if (r.Frequency > FrequencyType.Minutely && r.ByMinute.Count == 0 && referenceDate.HasTime
-                /* NOTE: Fixes a bug where all-day events have BySecond/ByMinute/ByHour added incorrectly */)
-            {
-                r.ByMinute.Add(referenceDate.Minute);
+                if (r.Frequency > FrequencyType.Secondly && r.BySecond.Count == 0 && referenceDate.HasTime
+                    /* NOTE: Fixes a bug where all-day events have BySecond/ByMinute/ByHour added incorrectly */)
+                {
+                    r.BySecond.Add(referenceDate.Second);
+                }
+                if (r.Frequency > FrequencyType.Minutely && r.ByMinute.Count == 0 && referenceDate.HasTime
+                    /* NOTE: Fixes a bug where all-day events have BySecond/ByMinute/ByHour added incorrectly */)
+                {
+                    r.ByMinute.Add(referenceDate.Minute);
+                }
+                if (r.Frequency > FrequencyType.Hourly && r.ByHour.Count == 0 && referenceDate.HasTime
+                    /* NOTE: Fixes a bug where all-day events have BySecond/ByMinute/ByHour added incorrectly */)
+                {
+                    r.ByHour.Add(referenceDate.Hour);
+                }
             }
-            if (r.Frequency > FrequencyType.Hourly && r.ByHour.Count == 0 && referenceDate.HasTime
-                /* NOTE: Fixes a bug where all-day events have BySecond/ByMinute/ByHour added incorrectly */)
+            else
             {
-                r.ByHour.Add(referenceDate.Hour);
+                // The BYSECOND, BYMINUTE and BYHOUR rule parts MUST NOT be specified
+                // when the associated "DTSTART" property has a DATE value type.
+                // These rule parts MUST be ignored in RECUR value that violate the
+                // above requirement(e.g., generated by applications that pre - date
+                // this revision of iCalendar).
+                r.BySecond.Clear();
+                r.BySecond.Add(0);
+                r.ByMinute.Clear();
+                r.ByMinute.Add(0);
+                r.ByHour.Clear();
+                r.ByHour.Add(0);
             }
 
             // If BYDAY, BYYEARDAY, or BYWEEKNO is specified, then
@@ -898,6 +915,14 @@ private Period CreatePeriod(DateTime dt, IDateTime referenceDate)
             return new Period(newDt);
         }
 
+        /// <summary>
+        /// Evaluate the occurrences of this recurrence pattern.
+        /// </summary>
+        /// <param name="referenceDate">The reference date, i.e. DTSTART.</param>
+        /// <param name="periodStart">Start (incl.) of the period occurrences are generated for.</param>
+        /// <param name="periodEnd">End (excl.) of the period occurrences are generated for.</param>
+        /// <param name="includeReferenceDateInResults">Whether the referenceDate itself should be returned. Ignored as the reference data MUST equal the first occurrence of an RRULE.</param>
+        /// <returns></returns>
         public override HashSet<Period> Evaluate(IDateTime referenceDate, DateTime periodStart, DateTime periodEnd, bool includeReferenceDateInResults)
         {
             if ((this.Pattern.Frequency != FrequencyType.None) && (this.Pattern.Frequency < FrequencyType.Daily) && !referenceDate.HasTime)