Calendar

The calendar overlays your tasks, subscription renewals, and custom events onto a single month grid. You control which of these appear, what color they use, and which projects' tasks to include.

What you can do

Open the Calendar to see the month at a glance, and use the Calendar settings to choose what shows up, set colors, and filter by project.

The calendar offers a month and a week view — switch between them from the header (there's no day mode). Use the previous, next, and today controls in the header to move around. Days from the neighboring months fill out the edges of the grid. The grid sizes itself to fit the screen between the top bar and the footer, so the whole month is visible without scrolling the page. The month you're viewing is remembered, so reopening the calendar returns you to where you left off; Today jumps back to the current month.

You can act directly on the grid:

Click a day to create — a quick-create dialog opens where you add either a custom event or a task on that date. For a task, the dialog opens with the deadline left empty — the task appears as a single day on that date. Drag across several days before releasing to create a task that spans the range, with its deadline set to the day you finish on.
Drag across the all-day row in week view — the strip above the hour grid, and the day headers above it, work the same way: drag across them and release to open the dialog over that day range, ready to create an all-day event. Dragging inside the hour grid below creates a timed event instead, over the hours you dragged.
Drag to reschedule — drag a task or custom event to another day to move it; only valid drop targets accept the drop.
"+N more" — when a day holds more chips than fit, the last slot becomes a +N more chip. Click it to expand that day in a small pop-up listing everything on it; the list scrolls if it's long. Chips stay draggable from the pop-up, so you can drag one straight onto another day to reschedule it (the pop-up closes as the drag begins).

In the create/edit dialog, Cmd/Ctrl+S saves without reaching for the button. When you open an existing task from the grid, the dialog also offers an Open full editor button that takes you to the task's full edit page for everything the quick dialog doesn't cover.

What appears on the grid

Several kinds of events show up as colored chips, and you can turn each on or off independently:

Tasks — a task with a deadline is drawn across every day from its start date to its deadline; a task without a deadline shows as a single chip on its start date. Both dates are optional for tasks, and a task with neither a start date nor a deadline does not appear on the calendar at all.
Custom events — all-day or timed, optionally repeating. Unlike tasks, an event always needs both a start and an end.
Subscription renewals — drawn from your active subscriptions.
Imported calendar events — from any external calendars you've subscribed to (see Imported calendars below).

Each built-in kind has its own visibility toggle and its own color. Tasks can also be tinted by their task type when the type has a color.

Custom events

A custom event has:

Title — required (up to 500 characters).
Description — optional (up to 5000 characters). The description supports rich text (formatting, lists, links) the same way task descriptions do.
Start and End — both required. This is the key difference from a task: an event always spans a from–to range, whereas a task can sit on a single day with no deadline.
Repeat — optional. It can repeat daily, weekly, monthly, or yearly, every N intervals.
Repeat end — optional: never end, end after a number of occurrences, or end on a date.

Editing a repeating event

When you edit or delete one occurrence in a repeating series, you choose how far the change reaches:

This occurrence — changes only the one you clicked.
All occurrences — changes or deletes the whole series.
This and following — ends the series at this occurrence.

A single occurrence can be skipped entirely or have its own title and times.

Imported calendars

You can subscribe to external calendars and see their events alongside everything else. Manage them on the Calendar imports page.

Add an import — paste a public calendar URL. Both standard https:// ICS links and webcal:// subscription links work. A name and color are optional.
Refresh — Ceum fetches each import when you add it and refreshes stale ones automatically (roughly every 15 minutes). You can also force a refresh from the imports page.
Enable / disable — turn an import off to hide its events without deleting it.
Errors — if a URL can't be fetched, the import shows the error so you can fix the link; the last good copy keeps showing in the meantime.

Imported events expand their recurrences server-side and appear as chips in their import's color.

Limitations. Imports are read-only — it's a one-way subscription, so changes you make in the source calendar flow in, but Ceum never writes back. Only public ICS / webcal URLs are supported; there's no Google or Outlook account connection and no CalDAV.

Weather

When weather data is available, each day cell shows a small weather icon. Hover it for current conditions — temperature and feels-like, wind, humidity, and pressure — plus a short forecast for the days ahead (up to five). Weather is powered by OpenWeather.

A Show weather toggle in Calendar settings turns the icons on or off (available on web and mobile). The location comes from a one-time browser geolocation prompt the first time you open the calendar. If you decline it, or your browser doesn't support geolocation, Ceum falls back to the capital city of your configured timezone so weather still shows. Temperatures are in Celsius and wind in metres per second.

Settings

The Calendar settings page lets you control:

Custom events

Event color — with a reset to the default.
Show events — toggle.

Tasks

Task color — with a reset to the default.
Show tasks — toggle.
Show all projects — when on, includes tasks from every project.
Project filter — when "Show all projects" is off, pick which projects to include. Your picks appear as removable tags.
Include tasks without a project — when on, shows tasks that aren't tied to any project.

Subscription renewals

Renewal color — with a reset to the default.
Show subscription renewals — toggle.

Save with the button in the bottom-right or with Cmd/Ctrl+S. The back button returns to the calendar without saving.

Tips and edge cases

Month and week views. Switch between them from the header; there's no day mode.
Tasks span their full date range. A task running from May 25 to May 30 shows up on every day in that range, not just on the deadline. A task with no deadline shows on its start date only — the deadline is optional, so editing such a task keeps the deadline empty unless you add one.
"This and following" is one-shot. Editing again with the same scope trims the series further from the new point.

On mobile

The mobile calendar mirrors the month grid with native gestures:

Long-press to drag-create — long-press an empty day and drag to select a range, with the range highlighted live; releasing opens a create sheet for the selected span. In week view the same long-press drag works across the day headers and the all-day row for an all-day span, and down the hour grid for a timed one.
Native sheets — tapping a day opens a day-detail sheet, and creating or editing events and imports uses bottom-sheet modals rather than the web dialogs. Imported events open in a read-only detail sheet.
Imports management — adding, editing, refreshing, and enabling external ICS / webcal calendars is available from the mobile settings, same as on the web.