diff --git a/generator/mavgen_wlua.py b/generator/mavgen_wlua.py
index 1960c6d66..f9dc3324f 100644
--- a/generator/mavgen_wlua.py
+++ b/generator/mavgen_wlua.py
@@ -66,7 +66,18 @@ def generate_preamble(outf):
 end
 local signature_time_ref = get_timezone() + os.time{year=2015, month=1, day=1, hour=0}
 
-time_usec_threshold = UInt64.new(0,4096)
+-- threshold to decide if time is absolute or relative (roughly 13.5 months from epoch)
+time_usec_threshold = UInt64.new(0,8192)
+-- function to append human-readable time onto unix_time_us fields
+local function append_time(subtree,value)
+    if value > time_usec_threshold then
+        d = os.date("%Y-%m-%d %H:%M:%S",value:tonumber() / 1000000.0)
+        us = value % 1000000
+        us = string.format("%06d",us:tonumber())
+        tz = os.date(" %Z",value:tonumber() / 1000000.0)
+        subtree:append_text(" [" .. d .. "." .. us .. tz .. "]")
+    end
+end
 
 payload_fns = {}
 
@@ -276,9 +287,7 @@ def generate_field_dissector(outf, msg, field, offset, enums, cmd=None, param=No
         if tvb_func == "le_uint64" and field.name in ["time_usec","time_unix_usec"]:
             t.write(outf,
 """
-    if value > time_usec_threshold then
-        subtree:append_text(" [" .. format_date(value:tonumber() / 1000000.0) .. "]")
-    end
+    append_time(subtree,value)
 """)
 
         if enum_obj and enum_obj.bitmask: