Date-Time Utility Library + Event Scheduler.

A modern desktop application built with Java Swing for managing events and performing various date/time calculations.

The Date-Time Utility Library is a comprehensive desktop application that combines time calculation utilities (like age calculation and time format conversions) with a robust event scheduler. It features a modern, clean UI with sidebar navigation, theme support, and a background daemon for real-time event reminders.

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Preview

(Note: Ensure docs/images/preview.gif is present to display the preview).

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Features

• Event Scheduler
  • Add, edit, and delete events.
  • Search and filter events by title, description, location, or date.
  • Priority levels for events (Low, Medium, High).
• Background Reminders
  • Configurable push notifications (JOptionPane) via a background daemon thread.
  • Reminder offsets: At time of event, 15 min, 30 min, 1 hour, or 1 day before.
• Time Utilities
  • View current time in customizable formats.
  • Calculate time differences between two times.
  • Convert between 12-hour (AM/PM) and 24-hour formats.
  • Add or subtract minutes from a given time.
• Age Calculator
  • Calculate exact age based on Date of Birth (Years, Months, Days).
  • Detailed age statistics (total weeks, days, hours, minutes, seconds).
  • Countdown to the next birthday.
• Data Persistence
  • Saves all events locally to a flat-file (events_data.txt), requiring no database setup.
• Modern User Interface
  • Swing-based UI with CardLayout for smooth navigation.
  • Sidebar with hover states and active-tab highlights.
  • (Planned) Dark/Light mode theme switching.

(Note: Date Utilities are currently planned/under construction).

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Tech Stack

• Programming Language: Java 17
• UI Framework: Java Swing
• Build Tool: Maven
• Database: Flat-file storage (events_data.txt) - No external SQL/NoSQL required.
• Dependencies: None (Core Java only)
• IDE: Any Java IDE (IntelliJ IDEA, Eclipse, VS Code).

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Project Structure

Date-Time-Utility-Library
├── docs/                   # Documentation and images.
├── src/main/java/
│   ├── app/
│   │   └── Main.java
│   ├── model/
│   │   └── Event.java
│   ├── scheduler/
│   │   └── EventScheduler.java
│   ├── storage/
│   │   └── FileManager.java
│   ├── ui/
│   │   ├── AddEvent.java
│   │   ├── CalendarView.java
│   │   ├── Dashboard.java
│   │   ├── ThemeManager.java
│   │   ├── custom/
│   │   │   ├── ModernButton.java
│   │   │   └── RoundedPanel.java
│   │   └── panels/
│   │       ├── AboutPanel.java
│   │       ├── AgeCalculatorPanel.java
│   │       ├── AllEventsPanel.java
│   │       ├── CalendarPanel.java
│   │       ├── DashboardPanel.java
│   │       ├── DateUtilityPanel.java
│   │       ├── EventSchedulerPanel.java
│   │       ├── SettingsPanel.java
│   │       └── TimeUtilityPanel.java
│   └── utility/
│       ├── AgeCalculator.java
│       ├── DateUtility.java
│       └── TimeUtility.java
├── .gitignore
├── LICENSE
├── pom.xml                 # Maven build configuration
└── README.md

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Installation

Follow these steps to run the project from scratch on your local machine:

1. Clone the repository

   git clone https://github.com/ashmitraj0344/Date-Time-Utility-Library.git

2. Navigate to the project folder

   cd Date-Time-Utility-Library

3. Install dependencies and Build project Since this is a Maven project, compile the source files using:

   mvn clean install

4. Run the project You can compile and run the application directly using javac and java:

   javac -d target -sourcepath src/main/java src/main/java/app/Main.java
   java -cp target app.Main

   Alternatively, open the project in your favorite IDE and run app.Main.java.

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Requirements

• Java Version: JDK 17 or higher.
• Maven: Version 3.6.0 or higher.
• Database: None required.
• OS: Windows, macOS, or Linux (requires GUI environment).

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Usage

1. Dashboard: Upon launching, the dashboard gives you a quick overview of your events. Use the left sidebar to navigate.
2. Adding an Event: Click on the "Event Scheduler" tab or use the "Add Event" dialog to create a new task. Fill out the mandatory Date (yyyy-MM-dd) and Time (HH:mm) fields.
3. Setting Reminders: When adding an event, check "Set Reminder" and choose your offset. Keep the app open; a popup will appear when the time arrives.
4. Time & Age Calculations: Navigate to the respective tabs in the sidebar, input your date/time, and see instant calculated results.

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Screenshots

Place the screenshots of your application in the docs/screenshots/ folder to display them here:

Dashboard	Add Event	Time Utilities

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Configuration

This project requires minimal configuration. Data is saved locally in the root directory as events_data.txt.

• No environment variables are necessary.
• The pom.xml handles the compiler configuration (Source/Target set to Java 17).

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Dependencies

The project relies entirely on Core Java (Standard Library).

• No external libraries (like Hibernate, Spring, or Apache Commons) are used, making it incredibly lightweight and easy to run anywhere.

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Architecture

The application follows a standard monolithic MVC-like (Model-View-Controller) pattern:

• Model: Represents the core data structures (e.g., Event.java).
• Storage Layer: FileManager.java intercepts model data and handles I/O operations (Serialization/Deserialization using a custom ||| delimiter).
• Scheduler/Service Layer: EventScheduler.java acts as the controller, maintaining the state of all events in memory and running a daemon Thread (startReminderCheckLoop()) to trigger UI callbacks.
• View (UI): Swing JFrame and JPanels that listen to the EventScheduler and update dynamically.

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Modules / Packages

• app: Contains the Main class which bootstraps the Swing UI and applies the cross-platform Look and Feel.
• model: Contains POJOs (Plain Old Java Objects) like Event representing the data.
• scheduler: Contains the core logic for filtering, searching, and managing the reminder thread.
• storage: Contains logic for reading/writing data to the filesystem safely.
• ui: Contains the main Dashboard frame, custom dialogs, and individual panels mapped to the sidebar navigation.
• utility: Contains static helper methods for pure calculations (AgeCalculator, TimeUtility).

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Future Improvements

• Fully implement the DateUtility functionality.
• Add recurring events (daily, weekly, monthly).
• Integrate an SQLite or H2 embedded database for better querying and indexing.
• Allow exporting events to .ics (iCalendar) format.
• Add drag-and-drop support in the Calendar View.

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Contributing

Contributions are welcome! To contribute:

1. Fork the repository.
2. Create a new branch: git checkout -b feature/YourFeatureName
3. Commit your changes: git commit -m 'Add some feature'
4. Push to the branch: git push origin feature/YourFeatureName
5. Open a Pull Request.

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License

This project is licensed under the MIT License - see the LICENSE file for details.

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Contributors

This project is collaboratively developed by:

• Aman Dwivedi
• Ashmit Raj
• Bhumika Suryawanshi
• Soumili Mandal
• Shubham Kumar
• Dinesh Bagariya
• Aniket / Aditya
• And other contributors

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Acknowledgements

• Built entirely with Java Swing and standard java.time APIs.
• UI inspiration and design principles adapted for modern desktop constraints.