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. It opens on Event; switch it to Task with the toggle at the top. The New item button in the header and the n shortcut open the same dialog, on today when today is on screen and otherwise on the first day of the period you're viewing. 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. Opening an item from the pop-up leaves the list standing behind it, so closing the item puts you back on the same day. Press Escape once to close the item and again to fold the list, or click anywhere outside it. 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, and a long description scrolls inside its own box rather than pushing the buttons out of reach. The dialog also offers an Open full editor button. It opens the full-page calendar form for either kind, carrying over what you have already filled in and offering the same Task and Event choice, so asking for more room never loses the kind you picked. On the task side that page is the whole task form — tags, priority, projects, custom fields, subtasks and relationships — so there is nothing left to go elsewhere for. Leaving that page — with Back or Escape — returns you to the calendar you came from.

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 an external calendar and see its events alongside everything else. Manage subscriptions on the Calendar imports page: paste a public ICS or webcal:// URL, optionally name it and give it a color, and its events appear as chips in that color, with anything that repeats expanded into its occurrences.

A subscription is one-way and its entries are read-only — they cannot be edited, deleted, or dragged, and the only way to change one is to change it in the calendar it comes from. Subscribing to an external calendar covers adding an import, which URL forms work, how often it refreshes, and what happens when a feed stops loading.

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.

Weather is the one part of the calendar that a plan gates: it is included on the Plus and Pro plans, and on any other plan the toggle and the icons are unavailable. Calendar imports, and the calendar itself, are on every plan.

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.