Tasks

Capture Tasks, set a Due Date when needed, and choose a Scheduled Date or Scheduled Date and Time to work on them.

Updated August 5, 2026

Tasks are the things you need to finish, not the places you need to be.

A Task can be as small as buying milk or as involved as preparing an assignment. It may have a Due Date, a Scheduled Date or Scheduled Date and Time, both, or neither.

Harmonise keeps Tasks beside the rest of your calendar. Prepare the figures for Monday can sit close to Project review on Monday without pretending they are the same kind of thing.

Together, Events and Tasks are your Plans. Events are the commitments in your calendar; Tasks are the work you need to complete. Open All Plans when you want to see either side of that picture without losing the other.

What makes something a Task?

A Task is something with a finish line. It stays open until you complete it, postpone it, change it, or delete it. The completion control is what makes a Task useful for something that might move around but still needs to be done.

Use a Task when the important question is, “Have I finished this?” Examples include calling the dentist, renewing a passport, packing for a trip, or sending a birthday present before it becomes a belated birthday present.

Use an Event when the important question is, “When is this happening?” Events are meetings, appointments, matches, calls, and other commitments with a particular time or place.

Task or Event?

The distinction becomes clearer when the two appear together:

Situation	Harmonise item
Sunday football from 8:00-10:00 AM	Event
Wash the football kit before Sunday	Task
League of Legends on Friday at 9:00 PM	Event
Install the update before Friday night	Task
Project review on Monday	Event
Prepare the figures before the review	Task

Sunday football is an Event because it happens at a set time. Washing the kit is a Task because it is something you need to finish before the Event.

You can also schedule a Task for a specific time. It still remains a Task because you can complete it, reopen it, and find it in your Task lists.

Start with only what you know

The only detail you normally need to begin is a title. Buy milk, Call the dentist, and Pack for the trip are all useful Tasks.

Leave a Task unscheduled when you know it needs doing but do not yet know when. Add a Due Date only when there is a real latest finish. Add a Scheduled Date when you know the day, or a Scheduled Date and Time when you know the exact slot. Description, duration, reminders, and subtasks can wait until they earn their keep.

Every standalone Task needs an eligible calendar selected or supplied by its creation flow. A screen may preselect a preferred calendar, but you still choose the calendar for the resulting Task. Harmonise does not silently assign one when no calendar was selected.

Due Date and Scheduled Date are different

A Due Date answers: When must this be finished?

A Scheduled Date answers: When will I do it? Add a time when you want a Scheduled Date and Time.

A Task can have neither, only a Due Date, only a Scheduled Date or Scheduled Date and Time, or both. A Due Date can likewise be date-only or an exact Due Date and Time. Keeping these ideas separate means you can rearrange your week without quietly changing what is due.

A Task may be scheduled before, at, or after its Due Date or Due Date and Time. If the planned work is later than the deadline, Harmonise may show a warning such as planned after deadline, scheduled after deadline, or may finish after deadline. The warning is informational; the schedule remains valid and saving is not blocked.

Moving a Due Date does not automatically move the Task’s Scheduled Date or Scheduled Date and Time. Scheduled-start reminders remain attached to the unchanged timed schedule.

For Wash the football kit, the Due Date and Time might be Sunday at 7:00 AM, before you leave. You might set the Scheduled Date and Time for Saturday at 7:00 PM. If Saturday gets busy, you can move it to Saturday afternoon. The Sunday Due Date and Time stays where it is.

For Submit the assignment, the Due Date and Time might be Friday at 5:00 PM. You could set the Scheduled Date and Time for Thursday from 7:00-9:00 PM. If you need a recovery plan, you can still schedule it later; Harmonise may warn you, but it will not require you to clear or reschedule the Task.

A Scheduled Date places the Task on a day. Adding a start and end time creates a Scheduled Date and Time, which gives it a specific slot in Agenda beside Events.

A complete Task example

Here is one Task with enough detail to be useful, without filling every available field:

Prepare for Sunday football

Calendar: Personal

Due Date and Time: Sunday at 7:00 AM

Scheduled Date and Time: Saturday at 7:00 PM

Estimated duration: 30 minutes

Reminder: Before the Scheduled Date and Time

Subtasks:

Wash the kit

Fill the water bottle

Check the location

The Due Date and Time protects the outcome. The Scheduled Date and Time makes room for the Task. The estimate helps you choose a sensible slot, and the subtasks keep the small preparations attached to one result.

On mobile

Open the Create menu and choose Task.
Enter Prepare for Sunday football as the Task title.
Choose the calendar name in the header, then select Personal. Calendars marked Read-only cannot receive a new standalone Task.
Choose Due, select Sunday, turn Include time on, and set 7:00 AM.
Choose Estimated duration and set 30 minutes.
Choose Add details if the rest of the form is not already open.
Choose Schedule, leave All-day off, set Saturday at 7:00 PM as the start, and set the end for 7:30 PM. Choose Done.
Under Reminders, add a reminder for Scheduled start at the amount of notice you want.
Under Subtasks, add Wash the kit, Fill the water bottle, and Check the location.
Choose Create.

To schedule the Task for Saturday without choosing a clock time, open Schedule and turn All-day on. It will appear with Saturday’s Plans without occupying an exact block in Agenda.

On web

Choose Create, then choose Task.
Enter Prepare for Sunday football in Task title.
Choose an eligible calendar in the Task form.
Add any useful context under Notes.
Under Due date, choose Add due date, then set Sunday at 7:00 AM.
Under Duration, choose 30m.
Under Scheduled time, choose Assign time, then set Saturday from 7:00-7:30 PM.
Choose the reminder that gives you enough notice.
Add Wash the kit, Fill the water bottle, and Check the location under Subtasks.
Choose Create task.

The same Task details can be adjusted later by opening the Task and choosing Edit task. Some web Task controls are still more limited than the mobile flow.

Add the details that help

Calendar

Choose the calendar that best explains where the Task belongs. A Personal calendar is a sensible home for groceries and football preparation; Work may suit a report or meeting preparation. Hiding a calendar can hide its Tasks from combined views, but it does not delete them.

A standalone Task must use an eligible writable calendar. A read-only calendar cannot receive a new standalone Task, and ordinary changes to a standalone Task can also be restricted while its current calendar is read-only. This can include editing, completion, subtask changes, and deletion. When allowed, a legacy Task can be moved from a read-only calendar to a writable calendar; a change that leaves it on the read-only calendar may still be blocked.

When a Task is linked to an Event, it uses that Event’s calendar. The calendar may be shown as From linked event instead of being independently selectable. An existing Task can be linked only when it already uses the Event calendar; linking does not silently move it. See Calendars with Events and Tasks and Writable and read-only calendars.

Due Date and Scheduled Date

Use Due for the latest acceptable finish. Use Schedule to choose a Scheduled Date, then add an exact start and end time when you need a Scheduled Date and Time. A Task may remain scheduled after its deadline; move the schedule earlier only if that helps you.

Every Task keeps one stored timezone for interpreting its own dates, schedules, and reminders. A standalone Task establishes this timezone when it is created. Direct editing does not replace it, and a profile or device timezone change does not rewrite it. A linked Task follows the Event timezone during link operations; see Tasks linked to Events.

Estimated duration

Estimated duration is how long you think the Task will take. Setting 30 minutes helps you choose a sensible slot, but it does not place the Task in your calendar by itself. Add a Scheduled Date or Scheduled Date and Time when you want to decide when you will do it.

Estimated duration is separate from schedule placement. It can be changed for a broader recurring Task scope where supported, while a Scheduled Date or Scheduled Date and Time belongs to one Task occurrence.

Reminders

Deadline reminders follow a Due Date, Due Date and Time, or an Event-controlled effective deadline. Scheduled-start reminders require a timed Scheduled Date and Time. A date-only Due Date uses the date-only reminder policy; it does not invent a midnight delivery time.

A Task can have up to two deadline reminders, up to two scheduled-start reminders, and up to four active reminders altogether. Reminder offsets are non-negative and must be a supported amount of time before the relevant deadline or scheduled start. Scheduled-start reminders always belong to This task. Clearing a timed schedule removes its scheduled-start reminders. Event reminders are separate from Task reminders.

When an eligible Task reminder becomes due, Harmonise creates a Task reminder in the Inbox. Push may also be sent when it is enabled and available. A failed or disabled push does not remove or resolve the Inbox reminder. The Task owner is currently the reminder recipient.

Moving a Due Date or linked Event recalculates eligible deadline reminders. It does not move scheduled-start reminders, which stay with the Task’s unchanged timed schedule.

Description and subtasks

Use the description field on mobile or Notes on web for information that helps you complete the Task: an address, a short brief, or what “done” should look like.

Subtasks are best when several small actions lead to one outcome. Prepare for Sunday football can contain washing the kit, filling the bottle, and checking the location. If a step needs its own Due Date, calendar, or Scheduled Date, make it a separate Task.

Subtask completion belongs to the selected Task occurrence. In the current mobile and web Task flows, completing the final unfinished subtask can also complete the parent Task, and reopening a subtask can reopen a completed parent. Harmonise coordinates the parent status separately from the individual subtask change. For a recurring Task, this affects only the selected occurrence; other occurrences remain unchanged. Completing the parent Task may also mark its subtasks complete where the current platform flow supports it. Use the parent Task completion control when you want to complete or reopen the whole Task directly.

Attachments

A persisted standalone Task can have up to five attachment slots. Its files belong to that Task and are currently private to the Task owner. Deleting the Task removes access to its attachments through the normal deletion lifecycle.

Files require an internet connection to upload or update. A file becomes available after it finishes processing successfully. Attachment operations are separate from the Task’s title, dates, and other core details.

Recurring Task attachments follow the Task series rather than individual occurrences. See Recurring Tasks for the series rules.

Offline and synchronization behavior

Harmonise can save some eligible core Task changes locally and synchronize them later. This can include supported Task creation, edits, completion, reopening, and deletion when the relevant local Task write path is active.

Offline eligibility is not universal. It can depend on the platform, local Task persistence, the Task calendar, the mutation scope, recurrence identity, server-owned side effects, or a synchronization conflict or repair state.

Files and some subtask, Event-link, recurring-series, provider-owned, or other server-owned operations still require a connection. Follow the visible sync status when a change remains pending. See Sync and offline use.

After you create a Task

On mobile, use Tasks in the month view or Lists in the week view for Tasks around the selected date. Next 3 days and Anytime help separate approaching Tasks from those with no schedule. Open All Plans to move between the Events and Tasks sides of your Plans. Within Tasks, use Active, Needs attention, Completed, Today, Anytime, Upcoming, Linked to events, and Recurring filters. A Task with an exact scheduled time also appears in Agenda.

On web, Month shows Tasks for the selected date in the Tasks panel. Agenda places scheduled Tasks beside Events and keeps unscheduled Tasks in the Tasks tray, where you can drag them into the schedule.

Use the checkbox beside a Task to complete it. Use the same control, or the Task menu, to mark it incomplete again. Open the Task and choose Edit task to change its details. Use the Task menu to edit, complete, reopen, or delete it.

Deleting a Task removes the Task. If it was linked to an Event, the Event remains in your calendar. For a repeating Task, Harmonise may first ask whether the change applies to this occurrence or a wider part of the series. See Recurring Tasks before making broad series changes.

Saved changes appear on your other signed-in devices after Harmonise finishes syncing. A pending change may need a refresh or a connection before it appears elsewhere; use the visible sync status rather than repeating the same edit on both devices.

Tasks and Events together

Events and Tasks make up your Plans, but they answer different questions. An Event tells you when something is happening. A Task tells you what still needs to be done.

For example, Project review is an Event because it happens at a set date and time. Prepare the figures is a Task that can be linked to that Event because it must be completed by the review.

A Task linked to a timed Event uses the Event’s start as its effective Due Date and Time. A Task linked to an all-day Event uses the Event’s first local date as its effective Due Date. The Task can still have its own Scheduled Date or Scheduled Date and Time, reminders, subtasks, attachments, and completion state.

When the Event moves, the Event-controlled deadline and eligible deadline reminders move with it. The Task’s Scheduled Date or Scheduled Date and Time does not move, and scheduled-start reminders remain tied to that unchanged timed schedule. If the schedule is later than the new effective deadline, the state remains valid; Harmonise may show a non-blocking warning, but saving is not blocked.

You can also add Tasks while creating or editing an Event. Linked Tasks have extra choices when an Event repeats, moves, or is deleted, so use Tasks linked to Events for that workflow.

Common problems

I cannot choose a calendar

Make sure the calendar is eligible and writable. A calendar marked Read-only cannot receive a new standalone Task, and ordinary changes may be restricted while a Task remains on it. Move a legacy Task to a writable calendar when that option is allowed, recreate the standalone Task in a writable calendar, or update the source calendar’s permissions.

My Task is not appearing in Agenda

Agenda shows Tasks with an exact timed Scheduled Date and Time. A Due Date or duration estimate alone does not reserve calendar time. Add a Scheduled Date and Time with a start and end time.

My schedule is later than the Due Date

That is a valid state. Harmonise may show a warning such as scheduled after deadline or may finish after deadline, but saving is not blocked. Move the Scheduled Date or Scheduled Date and Time earlier if you want the planned work to finish before the deadline; you do not have to clear or reschedule it.

The Task appeared on the wrong calendar

Open the Task and choose Edit task, then select the correct writable calendar when the Task is standalone. For an Event-linked Task, update the Event or unlink the Task first; linking does not silently move a Task between calendars.

A reminder did not appear as a push notification

Check the Task’s reminder and the device’s push preference. An eligible Task reminder still creates an Inbox reminder even when push is disabled, unavailable, or unsuccessful.

My changes have not appeared on another device

Check the visible sync status, reconnect if the operation requires a connection, and refresh the planning view. Do not repeat the same edit on both devices while one copy is still pending.