diff --git a/bashrc b/bashrc
index ceb302b..f347041 100755
--- a/bashrc
+++ b/bashrc
@@ -72,6 +72,10 @@ if iswindows; then
     export USER=$USERNAME
 fi
 
+_tmux_prefs(){
+    null type tmux || return 1
+    tmux set -g mode-keys vi
+}
 
 #######################
 
@@ -94,6 +98,9 @@ echo
 ( ! with_coreutils && isdarwin ) || iswindows || _timeoption=" --time-style=long-iso"
 ( ! with_coreutils && isdarwin ) || _hideoption=" --hide=[A-Z]*" # do not use
 
+_timeformat_iso="%Y-%m-%dT%H:%M:%S%z"
+_timeformat_rfc2822="%a, %d %b %Y %T %z"
+
 alias ls="ls -hCF${_coloroption}${_timeoption}"
 # export GREP_OPTIONS=""
 alias grep="grep -n${_coloroption}"
diff --git a/tmux.conf b/tmux.conf
index 1d4c436..35f2018 100644
--- a/tmux.conf
+++ b/tmux.conf
@@ -4,7 +4,8 @@ unbind C-b
 set -g prefix C-z
 bind-key C-z send-prefix
 bind-key C command-prompt "new-window '%%'"
-#setw -g mode-keys vi
+
+setw -g mode-keys vi
 
 set -g default-command /bin/bash
 #set -g default-terminal screen-256color