PerfectCalendar is a Open Source Windows program in the Other category, developed by Gsasl. The current version is 1.3.0; you can download it safely from its official source with the download button above.
PerfectCalendar is a pure C / Win32 API taskbar calendar that boots silently to the system tray and weighs ~230 KB on disk โ no .NET, no WebView2, no background sync daemon.
Key features: โข Flat-file event scheduling (events.dat โ plain text, always yours) โข MCM_SETDAYSTATE bitmask highlighting โ days with events appear bold โข Wildcard recurring events: ****-12-25 (yearly), ****-**-01 (monthly) โข Global hotkey (Ctrl+Shift+Space default) โ summons to your cursor โข Conflict-safe hotkey: shows tray notification instead of crashing โข Idle fade transparency via WS_EX_LAYERED โข ISO week-number column (MCS_WEEKNUMBERS) โข Multi-format date copy (ISO 8601, US, long form) โข UTC clock alongside local time โข HiDPI / 4K aware, mouse-wheel font zoom โข Explorer crash resilience (TaskbarCreated) โข All settings persisted to HKCU registry
โจ Features
calendartaskbartrayclockeventsschedulerwin32lightweightdark-mode
๐ Release notes (1.3.0)
v1.3.0 โ Full feature release [future updates required suggestions welcome]
NEW
โข Add-Event: inline subclassed EDIT control (Enter = save, Esc = cancel)
โข Recurring events: ****-MM-DD (yearly) and ****-**-DD (monthly)
โข Hotkey submenu in tray: 3 presets + Disabled, all check-marked
โข MOD_NOREPEAT on RegisterHotKey prevents key-repeat flooding
โข Tray balloon on hotkey conflict โ app keeps running normally
โข MCN_GETDAYSTATE bitmask bold-day highlighting (MCS_DAYSTATE)
โข ISO week-number column (MCS_WEEKNUMBERS)
โข Multi-format copy: ISO / US / long form via NM_RCLICK
โข UTC clock label (GetSystemTime)
โข Smooth idle transparency fade (WS_EX_LAYERED, TID_FADE timer)
โข Owner-drawn LISTBOX: recurring events in accent blue
โข F5 hot-reload events without restart
FIXED
โข Silent tray boot: ShowWindow removed from WinMain โ no more
aggressive popup on every system startup when Run on Startup enabled
โข SetWindowSubclass replaces legacy SetWindowLongPtr subclassing
โข hFontSmall / hSelBrush / hListBrush fully cleaned in WM_DESTROY
โข All timers explicitly KillTimer'd in WM_DESTROY
โข Mutex name versioned to avoid collision with older installs
All release notes โ โ
SHA-256: d93b8356fa3a01a2ea7cfc90436db13e5cb3a62831dd7dd69e4fed59c840b363 Check on VirusTotal โ