diff --git a/ProjectPlugins/CodexContractsPlugin/CodexContractsAccess.cs b/ProjectPlugins/CodexContractsPlugin/CodexContractsAccess.cs
index d6ba837..e4222d4 100644
--- a/ProjectPlugins/CodexContractsPlugin/CodexContractsAccess.cs
+++ b/ProjectPlugins/CodexContractsPlugin/CodexContractsAccess.cs
@@ -21,6 +21,7 @@ namespace CodexContractsPlugin
 
         Request[] GetStorageRequests(TimeRange range);
         EthAddress GetSlotHost(Request storageRequest, decimal slotIndex);
+        // add 'RequestFulfilled' to see request is started.
         SlotFilledEventDTO[] GetSlotFilledEvents(TimeRange timeRange);
         SlotFreedEventDTO[] GetSlotFreedEvents(TimeRange timeRange);
     }
diff --git a/TestNetRewarder/Configuration.cs b/TestNetRewarder/Configuration.cs
index cb9f95d..02401d2 100644
--- a/TestNetRewarder/Configuration.cs
+++ b/TestNetRewarder/Configuration.cs
@@ -16,7 +16,7 @@ namespace TestNetRewarder
         [Uniform("interval-minutes", "im", "INTERVALMINUTES", false, "time in minutes between reward updates. (default 15)")]
         public int Interval { get; set; } = 15;
 
-        [Uniform("check-history", "ch", "CHECKHISTORY", false, "if not 0, Unix epoc timestamp of a moment in history on which processing should begin. (default 0)")]
+        [Uniform("check-history", "ch", "CHECKHISTORY", true, "Unix epoc timestamp of a moment in history on which processing begins. Required for hosting rewards. Should be 'launch of the testnet'.")]
         public int CheckHistoryTimestamp { get; set; } = 0;
 
         public string LogPath
diff --git a/TestNetRewarder/TimeSegmenter.cs b/TestNetRewarder/TimeSegmenter.cs
index 3608c79..a9ad71a 100644
--- a/TestNetRewarder/TimeSegmenter.cs
+++ b/TestNetRewarder/TimeSegmenter.cs
@@ -14,15 +14,10 @@ namespace TestNetRewarder
             this.log = log;
 
             if (configuration.Interval < 0) configuration.Interval = 15;
+            if (configuration.CheckHistoryTimestamp == 0) throw new Exception("'check-history' unix timestamp is required. Set it to the start/launch moment of the testnet.");
+
             segmentSize = TimeSpan.FromSeconds(configuration.Interval);
-            if (configuration.CheckHistoryTimestamp != 0)
-            {
-                start = DateTimeOffset.FromUnixTimeSeconds(configuration.CheckHistoryTimestamp).UtcDateTime;
-            }
-            else
-            {
-                start = DateTime.UtcNow - segmentSize;
-            }
+            start = DateTimeOffset.FromUnixTimeSeconds(configuration.CheckHistoryTimestamp).UtcDateTime;
 
             log.Log("Starting time segments at " + start);
             log.Log("Segment size: " + Time.FormatDuration(segmentSize));
@@ -32,16 +27,21 @@ namespace TestNetRewarder
         {
             var now = DateTime.UtcNow;
             var end = start + segmentSize;
+            var waited = false;
             if (end > now)
             {
                 // Wait for the entire time segment to be in the past.
                 var delay = (end - now).Add(TimeSpan.FromSeconds(3));
+                waited = true;
                 await Task.Delay(delay, Program.CancellationToken);
             }
 
             if (Program.CancellationToken.IsCancellationRequested) return;
 
-            log.Log($"Time segment {start} to {end}");
+            var postfix = "(Catching up...)";
+            if (waited) postfix = "(Real-time)";
+
+            log.Log($"Time segment [{start} to {end}] {postfix}");
             var range = new TimeRange(start, end);
             start = end;