diff --git a/jc/parsers/last.py b/jc/parsers/last.py
index eb312416..22b99d19 100644
--- a/jc/parsers/last.py
+++ b/jc/parsers/last.py
@@ -2,6 +2,8 @@
 
 Supports -w and -F options.
 
+Calculated epoch time fields are naive (i.e. based on the local time of the system the parser is run on) since there is no timezone information in the `last` command output.
+
 Usage (cli):
 
     $ last | jc --last