diff --git a/README.md b/README.md
index 5d8c053..040f4cc 100644
--- a/README.md
+++ b/README.md
@@ -6,11 +6,12 @@ personal diary with txt style, can be private!
 
 ## environment variables
 
-|     name      |   description   |    required     |
-| :-----------: | :-------------: | :-------------: |
-| `TD_USERNAME` |    user name    |       no        |
-| `TD_USERPASS` |  user password  |       yes       |
-| `TD_PRIVATE`  | post visibility | empty = `false` |
+|        name        |      description      |    required     |
+| :----------------: | :-------------------: | :-------------: |
+|   `TD_USERNAME`    |       user name       |       no        |
+|   `TD_USERPASS`    |     user password     |       yes       |
+|    `TD_PRIVATE`    |    post visibility    | empty = `false` |
+| `TD_LOGINLIFETIME` | login lifetime (days) |   empty = `7`   |
 
 ## volumes (docker)