Jean-Luc Makiola
ef48717e2c
Code review of the one-visibility-model fix (#75) found the reconciliation reaching further than it should and the read-only case falling through it. The migration switched calendars *on* to keep the upgrade invisible, but "not disabled in Calendula" is the default for every calendar, including ones the user deliberately hid in Google Calendar, Etar or DAVx5 — those would reappear there and start firing reminders from a switch the user never touched. Its sync_events guard didn't hold either: an ACCOUNT_TYPE_LOCAL calendar another app created can sit at sync_events=0 while holding real device-local events. The reconcile now only hides, and a one-time notice explains that visibility follows the device and where to change it, instead of quietly rewriting other apps' state. Only READ_CALENDAR gates the app, so a read-only install could not write the flag at all: every calendar it had switched off came back with its events and its reminders, and the switch couldn't undo it. Those switch-offs are kept app-side now (the retired disabled-set key, re-read under a new name), folded into the visibility every consumer reads, and drained into the provider entry by entry once WRITE_CALENDAR arrives — which also makes a part-applied run resumable without re-applying a switch the user has since flipped by hand. Also: restore the ReminderNotifier.post gate, the one path a snooze re-shown from our own alarm passes; move the whole reconcile inside its try/catch, so a damaged preferences file can't crash the process at launch; share one Calendars query per provider tick across the flows that need it; and give the reworded Settings hint new keys, so five locales stop rendering the retired app-only wording. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Calendula
A modern Material 3 Expressive calendar for Android.
Reads, writes, and reminds — on top of the system calendar, with zero network access.
Calendula is named after the flower whose name — like the word calendar —
comes from the Latin kalendae, the first day of the month. It lives
entirely on top of Android's CalendarContract: any calendar synced to your
device (CalDAV via DAVx5, Google, local, WebCal subscriptions, …) simply
appears, and everything you create or edit syncs back the same way. No own
database, no sync stack reinvented.
✨ Features
Calendar
- Month, week, and day views with a one-tap view switcher
- Full event details — attendees and their responses, reminders, recurrence (humanized), availability, visibility, foreign time zones
- Per-calendar visibility toggle, grouped by account
Editing
- Create, edit, and delete events — including recurring events with scoped writes: only this event, this and all following, or the whole series
- Recurrence picker with one-tap presets and custom rules (interval, weekday toggles, end conditions); rules it can't express are preserved verbatim
- Conflict-safe saves: if an event changed elsewhere while you were editing, Calendula asks instead of silently overwriting
- Read-only calendars (WebCal, birthdays) are detected and respected
Reminders
- Event reminders delivered by Calendula itself as notifications — essential when it's your only calendar app, since Android delegates reminder delivery to calendar apps
- Tap a reminder to land on the event
Design & privacy
- Real Material 3 Expressive throughout — dynamic color (Android 12+), expressive motion and shapes, light/dark theme
- German and English UI, per-app language setting — and open to community translations
- Zero telemetry, zero analytics, no internet permission — your data never leaves the device
📦 Install
F-Droid (recommended)
Calendula is on the official F-Droid repository — just search for Calendula in any F-Droid client, or install it from f-droid.org.
Self-hosted repo (latest builds)
New versions are built, signed, and published to a self-hosted repository the moment each tag lands — usually a few days ahead of the official repo, which rebuilds on F-Droid's own schedule. Add it for the freshest builds:
-
In your F-Droid client, open Settings → Repositories → Add (or open the link below on your phone):
https://apps.dev.jeanlucmakiola.de/dev/fdroid/repo?fingerprint=C2C0640402BF458FC0ED957AF0B37AA4C14022E72F89CE90B5965B458CF73425Repo:
https://apps.dev.jeanlucmakiola.de/dev/fdroid/repo· fingerprint (SHA-256):C2C0 6404 02BF 458F C0ED 957A F0B3 7AA4 C140 22E7 2F89 CE90 B596 5B45 8CF7 3425 -
Refresh, search for Calendula, install.
Both channels share the same signing key, so you can switch between them without reinstalling. Or build from source — see below.
📚 Documentation
- Building from source — requirements and Gradle tasks
- Architecture — the layered design and key pipelines
- Roadmap — what's shipped and what's next
🌍 Translations
Calendula ships in German and English, and you're warmly invited to add your language. Translations are managed on a self-hosted Weblate:
No coding needed — register on the Weblate server, pick (or request) a language, and translate the strings in your browser. You can also reach this link in the app from the top of Settings → App language.
📜 License
MIT — Jean-Luc Makiola, 2026