diff --git a/.gitignore b/.gitignore
index 86a60e9..a7056d5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@
 /.nyc_output/
 /coverage/
 *.log
+*.d.ts
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc1968d..0ee3b33 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 1.2.0
+
+- added timing constants
+
 ## 1.1.0
 
 - added all documented http status codes
diff --git a/README.md b/README.md
index f9bba4b..ca1dbb6 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # @sapphirecode/consts
 
-version: 1.1.x
+version: 1.2.x
 
 useful constant values that are used in many applications
 
@@ -19,10 +19,35 @@ yarn:
 there are many constants, too many to document by hand so I suggest you use
 autocomplete or look into the source.
 
+Http status codes:
+
 ```js
 const {http} = require('@sapphirecode/consts');
 
-console.log(http.status_ok) // 200
+console.log(http.status_ok); // 200
+```
+
+Time
+
+```js
+const {time} = require('@sapphirecode/consts');
+
+console.log(time.base_ms.minute); // 60000
+```
+
+The time module contains a few precalculated bases like base_s, base_ms, base_us
+and base_ns. Those allow you to use timers without calculating everything
+first.
+
+> timer(base_ms.week) instead of timer(1000 x 60 x 60 x 24 x 7) or
+> timer(base_us.week) if your timer counts in microseconds
+
+time intervals above one week are functions, because they require additional
+information to be calculated
+
+```js
+console.log(time.base_ms.year(2020));
+console.log(time.base_ms.year(12, 2020));
 ```
 
 ## License
diff --git a/index.js b/index.js
index 0053084..4c24901 100644
--- a/index.js
+++ b/index.js
@@ -9,11 +9,13 @@
 'use strict';
 
 const http = require ('./http_status_codes');
+const time = require ('./time');
 
 module.exports = {
   http: {
     ...http.status_codes,
     ...http
-  }
+  },
+  time
 };
 
diff --git a/package.json b/package.json
index 5bf202f..76b9d2a 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@sapphirecode/consts",
-  "version": "1.1.28",
+  "version": "1.2.0",
   "main": "index.js",
   "author": {
     "name": "Timo Hocker",
@@ -28,8 +28,7 @@
   "files": [
     "LICENSE",
     "index.d.ts",
-    "index.js",
-    "http_status_codes.js"
+    "*.js"
   ],
   "keywords": [
     "constants",
diff --git a/time.js b/time.js
new file mode 100644
index 0000000..d904fd1
--- /dev/null
+++ b/time.js
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) Sapphirecode - All Rights Reserved
+ * This file is part of consts which is released under MIT.
+ * See file 'LICENSE' for full license details.
+ * Created by Timo Hocker <timo@scode.ovh>, December 2020
+ */
+
+/* eslint-disable sort-keys */
+'use strict';
+
+function is_leap (year) {
+  return year % 4 === 0 && (year % 100 !== 0 || year % 400 === 0);
+}
+
+function base (second = 1) {
+  const ms = second / 1000;
+  const us = ms / 1000;
+  const ns = us / 1000;
+  const minute = second * 60;
+  const hour = minute * 60;
+  const day = hour * 24;
+  const week = day * 7;
+
+  const year = (y) => {
+    const days = is_leap (y) ? 366 : 365;
+    return days * day;
+  };
+
+  const month = (m, y) => {
+    let days = 0;
+    if (m === 2)
+      days = is_leap (y) ? 29 : 28;
+    else if (m < 8)
+      days = 30 + (m % 2);
+    else
+      days = 31 - (m % 2);
+
+    return days * day;
+  };
+
+  return {
+    ns,
+    us,
+    ms,
+    second,
+    minute,
+    hour,
+    day,
+    week,
+    month,
+    year
+  };
+}
+
+module.exports = {
+  base_s:  base (1),
+  base_ms: base (1e3),
+  base_us: base (1e6),
+  base_ns: base (1e9),
+  base
+};