Coincide

See when your hours line up.

A minimalist macOS menu bar app + widget that keeps your home time and the zones you work with side by side — so remote workers never miscount the hours or miss a meeting again.

Built for the everyday remote-work question: "It's 4pm here — what time is it for my team in PST? Have they already gone home? Is it tomorrow there yet?" Coincide answers it at a glance, from the menu bar.

Screenshots

Menu bar popover — every zone with its flag, country, current time, a day/night indicator, and a Tomorrow / Yesterday tag when the date differs.

Main window — drag the time scrubber to shift time and watch every zone update together; the 24-hour day/night bands (navy night → warm day) line up on one axis, so you can instantly spot a slot that works for everyone.

Widgets — small and medium WidgetKit widgets for Notification Center and the desktop, sharing the same zones as the app.

Features

• 🕒 Menu bar at a glance — your chosen reference zone's flag + time, always visible and refreshed every minute.
• 📋 One-click popover — all your zones with flags, country names, GMT offsets, day/night glyphs, and day-difference tags.
• 🌅 Day/night, everywhere — a sun/moon indicator per zone, plus full 24-hour day/night bands in the dashboard, so you can see who's awake.
• 🎚️ Time scrubber — shift time across all zones on a shared axis to find overlapping working hours and meeting slots.
• 🧩 Widgets — small and medium WidgetKit widgets for Notification Center and the desktop, sharing the same data as the app.
• 📅 Calendar context (opt-in) — upcoming meetings in the popover and menu bar, shown across your zones, and as blocks on the day/night timeline. Read via Apple EventKit — events stay on your Mac, no network, nothing leaves the device.
• 🏠 Home + unlimited zones — auto-detects your home zone and lets you add as many comparison zones as you like from the full IANA catalog.
• 🪟 Lives in the menu bar — with a Dock icon only while a window is open.
• 🌗 12/24-hour, drag-to-reorder, launch-at-login.
• 🪶 Tiny & native — pure SwiftUI, no dependencies, App Sandbox, no network.

Connecting Google Calendar

Coincide reads Google events via OAuth (read-only, calendar.events.readonly). To enable it in your own build: create a Google Cloud project, enable the Calendar API, configure the OAuth consent screen (add yourself as a test user), create an iOS OAuth client, and put the client ID + reverse-client-id into Coincide/Calendar/GoogleConfig.swift and the CFBundleURLTypes entry in project.yml. Tokens are stored in the Keychain; nothing is sent anywhere but Google. Public distribution requires Google's one-time scope verification.

Architecture

Native SwiftUI. One Xcode project, three targets:

Target	Type	Purpose
Coincide	macOS app	MenuBarExtra popover, dashboard window, onboarding, Preferences
CoincideWidget	Widget extension	Small/medium WidgetKit widgets
CoincideKit (shared sources)	—	Models, store, time/day-night logic (compiled into the app, widget, and tests)

App and widget share state through an App Group (group.dev.bouncei.coincide) backed by a single JSON blob in UserDefaults. The time, GMT-offset, day-offset, and day/night logic lives in pure, unit-tested helpers in CoincideKit (20 tests).

CoincideKit/      SavedZone, ZoneStore, TimeFormatting, DayPhase, TimezoneCatalog, TimezoneCountries
Coincide/         App, MenuBar/, MainWindow/, Onboarding/, Settings/, Resources/
CoincideWidget/   WidgetBundle, TimelineProvider, views
CoincideKitTests/ formatting, store, and flag/country tests

Country flags and names are derived from the system zone.tab mapping (IANA zone → ISO country code) plus regional-indicator emoji and Locale.localizedString(forRegionCode:) — no bundled image assets.

Build & run

This repo uses XcodeGen so the Xcode project is generated from project.yml (and is git-ignored).

brew install xcodegen     # once
xcodegen generate         # generate Coincide.xcodeproj
open Coincide.xcodeproj

In Xcode, select the Coincide target → Signing & Capabilities → choose your Team (a free personal Apple ID works for local runs), then ⌘R.

Command line

# Run the unit tests (no signing required)
xcodebuild test -scheme Coincide -destination 'platform=macOS' \
  -only-testing:CoincideKitTests CODE_SIGNING_ALLOWED=NO

# Compile everything
xcodebuild build -scheme Coincide -destination 'platform=macOS' CODE_SIGNING_ALLOWED=NO

Shipping to the App Store

The project is structured App Store–ready (App Sandbox + App Group + hardened runtime). To submit you need a paid Apple Developer Program membership:

1. Set DEVELOPMENT_TEAM in project.yml (or pick your team in Xcode) and run xcodegen generate.
2. Register the App Group group.dev.bouncei.coincide and both bundle IDs (dev.bouncei.Coincide, dev.bouncei.Coincide.Widget) on the Developer portal — or let Xcode's automatic signing create them.
3. Reserve the App Store listing name in App Store Connect. The bare name "Coincide" is already taken, so reserve a qualified name such as "Coincide – Time Zones" — the app, bundle ID, and branding stay "Coincide".
4. Product → Archive → Validate App, then distribute.

Forking? Change the bundle ID prefix and App Group to your own reverse-DNS domain in project.yml and the two *.entitlements files.

Contributing

Contributions welcome — see CONTRIBUTING.md. Please run the test suite before opening a PR.

License

MIT © 2026 Joshua Inyang