Fix timestamp display issues with --annotate

nilmdb/utils/time.py

@@ -6,7 +6,7 @@ import time
 
 # Range
 min_timestamp = (-2**63)
-max_timestamp = (2**62 - 1)
+max_timestamp = (2**63 - 1)
 
 # Smallest representable step
 epsilon = 1
@@ -32,6 +32,10 @@ def timestamp_to_human(timestamp):
     """Convert a timestamp (integer microseconds since epoch) to a
     human-readable string, using the local timezone for display
     (e.g. from the TZ env var)."""
+    if timestamp == min_timestamp:
+        return "(minimum)"
+    if timestamp == max_timestamp:
+        return "(maximum)"
     dt = datetime_tz.datetime_tz.fromtimestamp(timestamp_to_unix(timestamp))
     return dt.strftime("%a, %d %b %Y %H:%M:%S.%f %z")
 

tests/test_cmdline.py

@@ -615,7 +615,7 @@ class TestCmdline(object):
         test(8, "10:01:59.9", "10:02:00.1", extra="-m")
 
         # all data put in by tests
-        self.ok("extract -a /newton/prep --start 2000-01-01 --end 2020-01-01")
+        self.ok("extract -a /newton/prep --start min --end max")
         lines_(self.captured, 43204)
         self.ok("extract -c /newton/prep --start 2000-01-01 --end 2020-01-01")
         self.match("43200\n")