diff --git a/src/luerl_lib_os.erl b/src/luerl_lib_os.erl
index 441b5f4..dc85d65 100644
--- a/src/luerl_lib_os.erl
+++ b/src/luerl_lib_os.erl
@@ -254,8 +254,13 @@ compute_time(Map=#{<<"year">> := Y, <<"month">> := Mth, <<"day">> := D}, _, St)
     LocalEpoch = calendar:universal_time_to_local_time({{1970,1,1},{0,0,0}}),
     Result = calendar:datetime_to_gregorian_seconds({{Y, Mth, D}, {H, Min, S}}) - calendar:datetime_to_gregorian_seconds(LocalEpoch),
     {[Result],St};
-compute_time(_, As, St) ->
-    badarg_error(time, As, St).
+compute_time(Map, _As, St) ->
+    MissingArg = lists:foldl(fun(K,Acc=undefined) -> case maps:is_key(K, Map) of
+                                                         false -> K;
+                                                         true -> Acc
+                                                     end;
+                                (_,Acc) -> Acc end, undefined, [<<"day">>, <<"month">>, <<"year">>]),
+    badarg_error(time, MissingArg, St).
 
 current_timestamp() ->
     {Mega,Sec,Micro} = os:timestamp(),