diff --git a/lib/open_exts.dart b/lib/open_exts.dart
index 7eb4c4c..8d5c283 100644
--- a/lib/open_exts.dart
+++ b/lib/open_exts.dart
@@ -1,7 +1,6 @@
 library open_exts;
 
-/// A Calculator.
-class Calculator {
-  /// Returns [value] plus 1.
-  int addOne(int value) => value + 1;
-}
+export 'src/color_extensions.dart';
+export 'src/datetime_extensions.dart';
+export 'src/duration_extensions.dart';
+export 'src/string_extensions.dart';
diff --git a/lib/src/color_extensions.dart b/lib/src/color_extensions.dart
new file mode 100644
index 0000000..ceaa6c2
--- /dev/null
+++ b/lib/src/color_extensions.dart
@@ -0,0 +1,16 @@
+import 'package:flutter/material.dart';
+
+extension OpenColorExtensions on Color {
+  Color fromHex(String hexString) {
+    final buffer = StringBuffer();
+    if (hexString.length == 6 || hexString.length == 7) buffer.write('ff');
+    buffer.write(hexString.replaceFirst('#', ''));
+    return Color(int.parse(buffer.toString(), radix: 16));
+  }
+
+  String toHex({bool leadingHashSign = true}) => '${leadingHashSign ? '#' : ''}'
+      '${alpha.toRadixString(16).padLeft(2, '0')}'
+      '${red.toRadixString(16).padLeft(2, '0')}'
+      '${green.toRadixString(16).padLeft(2, '0')}'
+      '${blue.toRadixString(16).padLeft(2, '0')}';
+}
diff --git a/lib/src/datetime_extensions.dart b/lib/src/datetime_extensions.dart
new file mode 100644
index 0000000..cffdb91
--- /dev/null
+++ b/lib/src/datetime_extensions.dart
@@ -0,0 +1,50 @@
+extension OpenDatetimeExtensions on DateTime {
+  static DateTime get _now => DateTime.now();
+
+  String nowString() => _now.toUtc().toIso8601String();
+
+  bool isToday() => _isSameDay(this, _now);
+
+  bool isYesterday() =>
+      _isSameDay(this, _now.subtract(const Duration(days: 1)));
+
+  bool isTomorrow() => _isSameDay(this, _now.add(const Duration(days: 1)));
+
+  bool isMorning() => hour >= 4 && hour < 12;
+  bool isAfternoon() => hour >= 12 && hour < 18;
+  bool isEvening() => hour < 4 || hour >= 18;
+
+  String getTimeOfDay() {
+    if (isMorning()) return 'morning';
+    if (isAfternoon()) return 'afternoon';
+    return 'evening';
+  }
+
+  DateTime findFirstDateOfTheWeek() => subtract(Duration(days: weekday - 1));
+
+  DateTime findLastDateOfTheWeek() =>
+      add(Duration(days: DateTime.daysPerWeek - weekday));
+
+  String formatSeconds(int value) {
+    final hours = (value ~/ 3600).toString().padLeft(2, '0');
+    final minutes = ((value % 3600) ~/ 60).toString().padLeft(2, '0');
+    final seconds = (value % 60).toString().padLeft(2, '0');
+    return "$hours:$minutes:$seconds";
+  }
+
+  String formatMinutes(int value, {bool allowZero = false}) {
+    final hours = (value ~/ 60).toString().padLeft(2, '0');
+    var minutes = (value % 60).toString().padLeft(2, '0');
+    if (minutes == '00' && !allowZero) minutes = '01';
+    return "$hours:$minutes";
+  }
+
+  DateTime get lastDayOfMonth =>
+      month < 12 ? DateTime(year, month + 1, 0) : DateTime(year + 1, 1, 0);
+
+  static bool _isSameDay(DateTime date1, DateTime date2) {
+    return date1.year == date2.year &&
+        date1.month == date2.month &&
+        date1.day == date2.day;
+  }
+}
diff --git a/lib/src/duration_extensions.dart b/lib/src/duration_extensions.dart
new file mode 100644
index 0000000..a85dfc9
--- /dev/null
+++ b/lib/src/duration_extensions.dart
@@ -0,0 +1,11 @@
+extension OpenDurationExtensions on Duration {
+  /// Converts the duration into a readable string in the format "HH:MM"
+  String toHoursMinutes() {
+    return "${inHours.toString().padLeft(2, '0')}:${inMinutes.remainder(60).toString().padLeft(2, '0')}";
+  }
+
+  /// Converts the duration into a readable string in the format "HH:MM:SS"
+  String toHoursMinutesSeconds() {
+    return "${toHoursMinutes()}:${inSeconds.remainder(60).toString().padLeft(2, '0')}";
+  }
+}
diff --git a/lib/src/string_extensions.dart b/lib/src/string_extensions.dart
new file mode 100644
index 0000000..f6ffd3f
--- /dev/null
+++ b/lib/src/string_extensions.dart
@@ -0,0 +1,36 @@
+extension StringExtension on String {
+  String operator -(String rhs) => replaceAll(rhs, '');
+
+  String truncateTo(int maxLength) =>
+      (length <= maxLength) ? this : '${substring(0, maxLength - 3)}...';
+
+  String shortenByWords(int maxLength) =>
+      shortenByDelimiterWithCount(maxLength);
+
+  String shortenByDelimiterWithCount(int maxLength, [String delimiter = ' ']) {
+    if (length <= maxLength) return this;
+
+    int endIndex = substring(0, maxLength).lastIndexOf(delimiter);
+    if (endIndex == -1) return substring(0, maxLength);
+
+    String shortened = substring(0, endIndex);
+    int remainingWordsCount =
+        split(delimiter).length - shortened.split(delimiter).length;
+    return remainingWordsCount > 0
+        ? '$shortened +$remainingWordsCount'
+        : shortened;
+  }
+
+  Iterable<String> splitByLength(int len, {String filler = '0'}) sync* {
+    String paddedString = padRight((length + len - 1) ~/ len * len, filler);
+    for (var i = 0; i < paddedString.length; i += len) {
+      yield paddedString.substring(i, i + len);
+    }
+  }
+
+  String capitalize() =>
+      length > 0 ? substring(0, 1).toUpperCase() + substring(1) : this;
+
+  String decapitalize() =>
+      length > 0 ? substring(0, 1).toLowerCase() + substring(1) : this;
+}
diff --git a/pubspec.yaml b/pubspec.yaml
index 85e0a8b..6905778 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,7 +1,9 @@
 name: open_exts
 description: "Extensions. Its that simple..."
 version: 0.0.1
-homepage:
+homepage: http://reinemuth.rocks:3000/jens/open_exts
+publish_to:
+
 
 environment:
   sdk: ^3.5.4
diff --git a/test/open_exts_test.dart b/test/open_exts_test.dart
deleted file mode 100644
index d960d9e..0000000
--- a/test/open_exts_test.dart
+++ /dev/null
@@ -1,12 +0,0 @@
-import 'package:flutter_test/flutter_test.dart';
-
-import 'package:open_exts/open_exts.dart';
-
-void main() {
-  test('adds one to input values', () {
-    final calculator = Calculator();
-    expect(calculator.addOne(2), 3);
-    expect(calculator.addOne(-7), -6);
-    expect(calculator.addOne(0), 1);
-  });
-}