Horolog vs Open Sunsama
Horolog
github.comOpen Sunsama
opensunsama.comSide by side
| Figure | Horolog | Open Sunsama |
|---|---|---|
| Price from | — | Free |
| Free plan | — | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| iOS | — | Yes |
| Android | — | Yes |
| API | — | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 0 | 2 |
| Spec score · AI Calendar Assistants | 7.3 (#23) | 8.5 (#4) |
| License | Horolog is licensed AGPL-3.0-or-later, and the README says modified network-service versions must publish their changes. | The repository uses a custom Open Sunsama Non-Commercial License dated 2024–2026, permitting personal, educational, nonprofit, non-commercial open-source, and evaluation use. |
| Product | Horolog is an open-source, self-hosted AI calendar that schedules focus time, habits and tasks around meetings. | Open Sunsama is a task manager and daily planner with a board of days and calendar time blocking. |
Plans
In their own words
Open Sunsama
Open Sunsama is a task manager and daily planner built around a board of days and calendar time blocking. Move tasks from a backlog to a daily board; unfinished work rolls over to tomorrow. Focus mode times a task and tracks actual time against its estimate. It syncs Google Calendar, Outlook, and iCloud, with support for multiple accounts. Time blocks stay in Open Sunsama rather than being copied to Google or Outlook calendars. Its hosted MCP server connects to Claude, ChatGPT, Cursor, and other MCP clients through OAuth and provides 24 tools. The REST API covers tasks, subtasks, and time blocks, with selectable API-key scopes. Users can also self-host the web app, API, MCP server, and PostgreSQL database using Docker Compose. The free plan costs nothing for personal use. The non-commercial license limits production use by companies, and there is no one-click export button. Desktop apps are available for Mac, Windows, and Linux; phones use the mobile web app, as no native phone app is available yet.