NativeCal

NativeCal is a local-first native Windows calendar app built with WinUI 3 and SQLite.

It focuses on a polished desktop experience with fast calendar navigation, multiple views, editable events, multiple calendars, built-in holiday calendars, and solid regression coverage for the non-UI logic.

Features

• Month, Week, Day, and Agenda views
• Multiple calendars with color coding and visibility toggles
• Event create / edit / delete flows
• All-day and timed events
• Drag-and-drop / resize interactions in the calendar UI
• Built-in US and Canada holiday calendars
• Theme settings: System, Light, Dark
• First day of week setting: Sunday, Monday, or Saturday
• Default reminder setting for new events
• Localized time / weekday formatting based on the active culture
• SQLite-backed local storage with no account required

Tech Stack

• .NET 10
• WinUI 3 / Windows App SDK
• CommunityToolkit.Mvvm
• sqlite-net-pcl
• xUnit for regression tests

Project Structure

NativeCal/         Main WinUI desktop application
NativeCal.Tests/   Unit and regression tests
ScreenCap/         Utility project
clicker/           Utility project

Getting Started

Requirements

• Windows
• .NET 10 SDK
• x64 environment

Restore

dotnet restore Native-Cal.sln

Build

dotnet build Native-Cal.sln --nologo

Run

dotnet run --project NativeCal/NativeCal.csproj

Test

dotnet test Native-Cal.sln --nologo

Notes

• App data is stored locally in SQLite under the user profile.
• Holiday data is fetched from the public Nager.Date API.
• Recurrence selection currently exists in the UI, but full recurrence expansion is not implemented yet.
• Tests focus on models, helpers, services, and view-model behavior.

Recent Polish Work

This repo includes fixes and regression coverage for:

• all-day event range handling
• calendar deletion invariants
• agenda and month multi-day overlap handling
• reminder/default-draft behavior
• localization-sensitive date/time display
• reserved holiday calendar name protection
• stale update protection in the data layer

License

This project is licensed under 0BSD (Zero-Clause BSD).

That means people can use, copy, modify, publish, and distribute it with essentially no restrictions, subject to the standard no-warranty disclaimer.

See LICENSE.