3MC was removed from the App Store in November 2022, but will be back.

I still use 3MC daily, along with several long-time users, and I have several planned improvements and great user feedback to implement. But it’s a side project to my main app, TimeStory, which has a very full plan for 2022/23, so those plans will take a little time. Meanwhile, I’ve also recently had one report of a pretty serious problem, which I’m not yet sure I have the right fix for.

So I’ve pulled the app from new sales. Existing installations should work just fine, and please reach out if you have any feedback or need any support. I’ll keep working on it on the side, and when it’s ready, I’ll be bringing it back.

Thanks for your support! I’ve left the rest of this page in place, as a reference. (And as a teaser!)

Contents: About | Help & Usage | Contact & Support | Acknowledgments | Release History

About 3MC

Three Month Calendar is a new and unique calendar-viewing app for your Mac’s menu bar. Fast and compact, it shows three months’ worth of weeks in a scrolling view, making it quick to answer questions about days, weeks, or upcoming events:

Screenshot of Three Month Calendar opened beneath its Mac menu bar item
The basic Three Month Calendar view

You can also integrate your personal calendars into the display. To keep the view compact and glanceable, 3MC lets you choose from a selection of marker types for any calendar you enable. These marker types use different positions and shapes, so they’re quick to spot, and combine well on busy days:

Screenshot of 3MC, with the Markers preferences tab open, and various days on the calendar marked
Optionally add markers to days based on calendar events

It has a variety of style and configuration options, and supports a systemwide keyboard shortcut as well as the Shortcuts app. Scroll down for a full walkthrough and help, or drop an email with any questions.

3MC is available on the Mac App Store. Up-front purchase; no ads, no subscriptions.

Help & Usage

First-time setup

When you first launch 3MC, an intro window will appear. You probably want to check the “Start 3MC automatically” box. You can always change this later; see configuring startup, below.

Screenshot of 3MC's initial welcome window
First-time welcome window

General usage

Click on the menu bar icon to open or close 3MC. While open, it stays on top of all other windows and won’t take keyboard focus, so you can leave it up while working on other things.

With the calendar open, you can freely scroll up or down a few more months. If you scroll far enough in either direction, you’ll reach the end of the currently-loaded weeks; after you stop scrolling, 3MC will fill in more weeks in that direction.

(3MC currently loads 65 weeks at a time; 15 visible weeks plus 25 weeks in either direction. This ensures that three full months are always visible, and that roughly a year’s worth of time is easily scrollable.)

Right-click on the menu bar icon and choose Preferences to adjust the app’s configuration.

Configuring 3MC’s appearance

The Style tab lets you configure what parts of the calendar are shown and what theme is used. There are also two sizes available, depending on whether you want bigger text or a more compact presentation.

Screenshot of 3MC's Style preferences pane
Style-related preferences

Configuring day markers and calendar access

The Markers tab of the preferences window lets you configure day markers. Today’s date is a built-in, or “standard”, marker, and you can adjust its appearance here.

You can also choose a marker to apply based on events from your macOS Calendar app. Click Enable next to “My Calendars” to load the list of available calendars; if this is the first time you’re doing so, macOS will prompt you for permission.

Screenshot of 3MC's Markers preferences pane
Markers preferences, before and after enabling calendar access

For any calendar marker, you can choose from a fixed set of marker types. This includes a few different background shapes, and underline, and a mark in any of the four corners of a date.

The calendar-event colors reflect the same colors used in the Calendar app; go to that app to adjust them. For today’s date, you can adjust the color directly within 3MC.

Viewing events

When a calendar day has one or more event markers on it, simply hover your mouse over it to see a brief summary. The squares reflect the calendar colors, and the events’ titles and time ranges are shown.

Screenshot of 3MC, with event details visible for a day
The mouse is over March 8, so the events which caused its marker are shown.
I made this up; I don't know anyone named J whose birthday is the 8th.

Configuring the 3-month view and pop-up event details

The “Options” tab in Preferences has two adjustments:

Screenshot of 3MC's Options preferences pane
Other options

Configuring startup

To configure automatic startup at any time, use the Startup pane of the Preferences window.

Screenshot of 3MC's Startup preferences pane
Startup preferences

If this is unchecked, the 3MC button will disappear from your menu bar whenever you log out and log back in (or restart your Mac). If this is checked, it will automatically show up.

(Technical note: 3MC installs itself by registering its own “3MC Launch at Login Helper” app with the system. This is separate from the Login Items list you’ll see in System Preferences, because Apple prevents sandboxed apps like 3MC from modifying that list.)

Configuring the keyboard shortcut

Click on the menu bar icon to pop open the calendar. Click on that icon again to dismiss it. You can also set up a global hot key:

Screenshot of 3MC's Shortcut preferences pane
Startup preferences

Note on languages and regions

3MC was designed to adopt your Mac’s system-wide date format settings. I’ve personally tested it with a fair number of languages and settings, but it’s possible you’ll use a combination which doesn’t look quite right; let me know and I’ll try to fix it. (3MC’s menus and dialogs are all in US English, however.)

Contact & Support

Questions? Problems? Feature requests? Complaints? Praise? Drop me a line at 3mc@casualprogrammer.com.

3MC is a side project; my energy is mostly on TimeStory. But I’d love to make it as useful and fun as possible, while keeping it small, fast, and focused.

If you’d like to review 3MC, feel free to use the screenshots on this page, and drop me a line with any questions.


3MC 2 uses Sindre Sorhus’s very nice KeyboardShortcuts package for Swift. This provides the code to choose and handle global Mac keyboard shortcuts. It’s easy to use, well-documented, and available under the MIT license.

Release History

Orange Beach, Alabama

…is where I took the photo in the desktop background.