PerfectCalendar is a pure C / Win32 API taskbar calendar that boots silently to the system tray and weighs ~230 KB on disk — no .NET, no WebView2, no background sync daemon. Key features: • Flat-file event scheduling (events.dat — plain text, always yours) • MCM_SETDAYSTATE bitmask highlighting — days with events appear bold • Wildcard recurring events: -12-25 (yearly), --01 (monthly) • Global hotkey (Ctrl+Shift+Space default) — summons to your cursor • Conflict-safe hotkey: shows tray notification instead of crashing • Idle fade transparency via WS_EX_LAYERED • ISO week-number column (MCS_WEEKNUMBERS) • Multi-format date copy (ISO 8601, US, long form) • UTC clock alongside local time • HiDPI / 4K aware, mouse-wheel font zoom • Explorer crash resilience (TaskbarCreated) • All settings persisted to HKCU registry
What's new in 1.3.0
v1.3.0 — Full feature release [future updates required suggestions welcome]
Owner-drawn LISTBOX: recurring events in accent blue
F5 hot-reload events without restart
FIXED • Silent tray boot: ShowWindow removed from WinMain — no more aggressive popup on every system startup when Run on Startup enabled • SetWindowSubclass replaces legacy SetWindowLongPtr subclassing • hFontSmall / hSelBrush / hListBrush fully cleaned in WM_DESTROY • All timers explicitly KillTimer'd in WM_DESTROY • Mutex name versioned to avoid collision with older installs
Yes. PerfectCalendar is free and open-source software released under the MIT license.
What is the latest version of PerfectCalendar?
The latest version is 1.3.0.
Is it safe to download PerfectCalendar?
The download button links to the official installer published on github.com, the same file Windows Package Manager installs. You can verify the downloaded file by comparing its SHA-256 checksum with d93b8356fa3a01a2ea7cfc90436db13e5cb3a62831dd7dd69e4fed59c840b363.
Which Windows versions does PerfectCalendar support?
PerfectCalendar requires Windows 10 version 1809 or later and is available for 64-bit (x64) systems.
How do I uninstall PerfectCalendar?
Open Settings › Apps › Installed apps, find PerfectCalendar and select Uninstall. From the command line, run winget uninstall --id=Gsasl.PerfectCalendar -e.
Is there a portable version of PerfectCalendar?
Yes. PerfectCalendar is available as a portable program (PerfectCalendar.exe, 64-bit (x64)) that runs without installation. Copy it to any folder or USB drive and run it from there.
Alternatives to PerfectCalendar
Other Project Management programs for Windows from different developers.
