diff --git a/seinflux.py b/seinflux.py
index 027630e..bef772a 100644
--- a/seinflux.py
+++ b/seinflux.py
@@ -3,8 +3,12 @@ from pathlib import Path
 from configparser import ConfigParser
 from sehistory.influx import InfluxDBWrapper, abs_range, round_range, Table
 
+ETERNITY = 1e10
+
 
 def fmtime(t):
+    if t >= ETERNITY:
+        return '-' * 19
     return time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(int(t)))
 
 
@@ -261,7 +265,6 @@ class SEHistory(InfluxDBWrapper):
 
         interval = 1
         gap = 600
-        eternity = 1e10
         if start is None:
             previous = {}
         else:
@@ -331,9 +334,9 @@ class SEHistory(InfluxDBWrapper):
                         if chunks and time.localtime(chunks[-1][0])[:3] == time.localtime(ts)[:3]:
                             # merge when started at the same day
                             chunk = chunks[-1][1]
-                            chunk[1] = eternity
+                            chunk[1] = ETERNITY
                         else:
-                            chunk = [ts, eternity]
+                            chunk = [ts, ETERNITY]
                             chunks.append(chunk)
                     else:
                         chunk = None