diff --git a/o_manager.py b/o_manager.py
index c6c3928..197e7bf 100644
--- a/o_manager.py
+++ b/o_manager.py
@@ -113,7 +113,7 @@ class OManager:
                 prev_value = value
             ping_stat = i["op"].get_ping_stat(lines=lines)
             ping_tas = TimeSeriesAccumulator(
-                start_time=now-timedelta(minutes=time_range), end_time=now, n_bins=n_bins)
+                start_time=now-timedelta(minutes=time_range), end_time=now, n_bins=n_bins, alignment=self.monitor_interval)
             for line in ping_stat:
                 time, value = line.split(",")
                 time = datetime.utcfromtimestamp(float(time))
diff --git a/plot_gen.py b/plot_gen.py
index fdac46a..2d91af9 100644
--- a/plot_gen.py
+++ b/plot_gen.py
@@ -23,7 +23,7 @@ class TimeSeriesAccumulator:
 
     def add(self, time, value):
         timestamp = time.replace(tzinfo=timezone.utc).timestamp()
-        if time < self.start_time or time > self.end_time:
+        if timestamp < self.start_timestamp or timestamp > self.end_timestamp:
             return
         idx = int((timestamp - self.start_timestamp)/self.bin_time)
         self.data[idx].append(value)
@@ -46,7 +46,7 @@ class TimeSeriesAccumulator:
 
 if __name__ == "__main__":
     tsa = TimeSeriesAccumulator(start_time=datetime(
-        2020, 7, 27, 23, 0, 0), end_time=datetime(2020, 7, 28, 0, 0, 0), n_bins=2)
+        2020, 7, 27, 23, 0, 33), end_time=datetime(2020, 7, 28, 0, 0, 43), n_bins=2, alignment=5)
     tsa.add(datetime(2020, 7, 27, 23, 15, 0), 1)
     tsa.add(datetime(2020, 7, 27, 23, 45, 0), 2)
     tsa.add(datetime(2020, 7, 27, 22, 45, 0), 3)