Also add warning if event time delta is greater than 5 minutes

backend/scripts/ztplot.py

@@ -207,9 +207,13 @@ class ZTPlot(kp.Module):
             dt = datetime.utcfromtimestamp(utc_timestamp)
         except OverflowError:
             self.log.critical("OverflowError encountered when converting '%s' to "
-                              "a datetime object." % utc_timestamp)
+                              "a datetime object.", utc_timestamp)
             dt = "invalid date"
 
+        delta_t = (datetime.utcnow() - dt).seconds
+        if abs(delta_t) > 60*5:
+            self.log.warning("The timestamp-delta of the event is '%s'", delta_t)
+
         title = "z-t-Plot for DetID-{0} Run {1}, "  \
                 "FrameIndex {2}, TriggerCounter {3}, Overlays {4}, "  \
                 "Trigger: {5}\n{6} UTC".format(