Tasks linked to Events

Connect preparation work due by one Event, future Events, or an entire recurring Event series.

Updated August 5, 2026

Before you begin

An Event in an eligible writable calendar

Tasks linked to Events are useful when work must be completed by an Event in your calendar.

For example, Project review is an Event because it happens at a set date and time. Prepare the figures is a Task because it is work that needs to be completed before the review.

Linking the Task keeps preparation work connected to the Event without turning the Task into an Event.

What changes when a Task is linked?

The linked Event controls:

the Task’s calendar;
the Task’s effective deadline; and
the Task’s relationship to an Event recurrence.

For a timed Event, its start becomes the Task’s effective Due Date and Time. For a one-day all-day Event, its local Event date becomes the Task’s effective Due Date. For a multi-day all-day Event, its first local Event date becomes the Task’s effective Due Date. An all-day Event does not invent an exact deadline time.

The Task does not have an independent Due Date or Due Date and Time, calendar, or Task recurrence rule while it remains linked to the Event.

The Task can still have its own:

title;
description or notes;
Scheduled Date or Scheduled Date and Time;
estimated duration;
Task reminders;
subtasks;
attachments; and
completion state.

Event-aligned calendar and timezone

Every Event has one immutable Event timezone. A new Task created from an Event uses the Event calendar and adopts the Event timezone.

An existing Task can be linked or relinked only when it already uses the Event calendar. Linking or relinking aligns the Task’s stored timezone with the Event timezone; it does not silently move the Task to another calendar. While the Event relationship controls the Task, the Task does not expose an independently selectable timezone.

The linked Task still stores its Task timezone and uses it for Task-owned date, schedule, and reminder interpretation. Ordinary movement of the Event does not change the Event timezone. Unlinking preserves the last timezone the Task adopted from the Event. A profile or device timezone change does not replace the stored Task timezone.

For example:

Project review

Event Date and Time: Monday at 10:00 AM - 11:00 AM

Event timezone: the timezone saved on the Event

Prepare the figures

Effective Due Date and Time: Monday at 10:00 AM

Scheduled Date and Time: Friday at 03:00 PM - 04:00 PM

Estimated duration: 60 minutes

Subtasks:

Check the latest figures

Update the charts

Send the draft

Effective deadline and Task-owned schedule

The Event supplies the effective deadline. The Task’s Scheduled Date or Scheduled Date and Time tells Harmonise when you plan to do the work.

A Task may remain scheduled before, at, or after the Event-controlled deadline. If it is later, Harmonise may show a warning such as scheduled after deadline or may finish after deadline. The warning is non-blocking and saving remains allowed.

Moving the Event changes the linked Task’s effective deadline. For a timed Event, the new start becomes the new effective Due Date and Time. For an all-day Event, the new first local Event date becomes the new effective Due Date. Eligible deadline reminders are recalculated.

The Task’s Scheduled Date or Scheduled Date and Time does not move automatically. Scheduled-start reminders remain attached to the Task’s unchanged timed schedule. Move the schedule earlier only if you want the planned work to happen before the new deadline; you do not have to clear or reschedule it.

Link a Task to an Event

On mobile

Open the Create menu and choose Task, or open an existing Task for editing.
Enter the Task title or open the existing Task’s linked Event field.
Choose the Event the Task belongs to.
Add a Scheduled Date when you want to decide the day for the work, and a time when you need an exact Scheduled Date and Time.
Add reminders, subtasks, estimated duration, attachments, or a description when they help.
If the Event repeats, choose how broadly the Task should be attached.
Choose Create or save the Task.

The Task uses the Event’s calendar and timezone, so those fields are not selected independently. An existing Task can be linked only when it is already in the same calendar as the Event. Harmonise does not move it to another calendar as part of linking.

On web

Choose Create, then choose Task, or open a Task and choose Edit task.
Use the linked Event control to choose the Event.
Add the Task title and any useful notes, Scheduled Date or Scheduled Date and Time, duration, reminders, subtasks, or attachments.
If the Event repeats, choose how broadly the Task should be attached.
Choose Create task or save the edit.

The web Task form shows the Event-controlled calendar and uses the Event-aligned Task timezone instead of offering conflicting standalone choices. Linked Tasks can also be added from the Event editing flow where that control is available. The web entry points and surrounding controls are still more limited than the mobile flow.

Choose which Events receive the Task

A one-time Event receives one linked Task. A recurring Event gives you three Event attachment choices. These are different from the ordinary Task mutation scopes This task, This and future tasks, and Entire series.

This event only

Choose This event only when the Task belongs only to the selected Event.

The selected Event receives the Task.
Earlier Events do not receive the Task.
Later Events do not receive the Task.
The Task does not repeat with the Event series.

For example, add Bring the signed form only to next Monday’s appointment.

This and future events

Choose This and future events when the Task should begin with the selected Event and continue with later Events.

The selected Event receives the Task.
Eligible later Events receive the Task.
Earlier Events do not receive the Task.
The Task repeats by following the recurring Event.
The Task does not have its own Task repeat rule.

For example, add Prepare the weekly figures to this Monday’s review and every later weekly review.

Entire series

Choose Entire series when the Task belongs to every eligible Event in the series.

Eligible earlier Events receive the Task.
The selected Event receives the Task.
Eligible future Events receive the Task.
Deleted, excluded, or otherwise nonexistent Event occurrences do not receive the Task.
The Task repeats by following the recurring Event.
The Task does not have its own Task repeat rule.

The difference is important: This and future events begins from the Event you selected, while Entire series also includes eligible earlier Events.

When the Event calendar changes

A linked Task always uses the Event’s calendar. Changing the Event calendar updates eligible Tasks that remain linked to that Event or Event series. The Task does not keep an independently selectable calendar while it is linked.

When linking an existing standalone Task, it must already be in the Event’s calendar. Harmonise does not silently move it as part of linking. To place it in a different calendar, move it while it is standalone when that move is allowed, or unlink it before changing its calendar.

Read-only calendars can restrict ordinary Task changes. An unchanged Event link may have limited exceptions for unlinking or deletion, but the practical choice is to use an eligible writable Event calendar or update the source calendar’s permissions.

Reminders and subtasks

A linked Task can use two kinds of reminders:

deadline reminders based on the Event-controlled effective deadline; and
scheduled-start reminders based on the Task’s own timed Scheduled Date and Time.

One 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 apply to This task only; they do not copy to future Tasks and are removed when the timed Scheduled Date and Time is cleared.

Moving the Event updates eligible deadline reminders that follow the Event-controlled deadline. Scheduled-start reminders remain tied to the Task’s unchanged Scheduled Date and Scheduled Date and Time.

When an eligible Task reminder becomes due, Harmonise creates a Task reminder in the Inbox. Push may also be sent when enabled and available. A push failure or disabled push preference does not remove the Inbox reminder, and the Task owner is currently the reminder recipient. Task reminders are separate from Event reminders.

Subtasks remain part of the Task. Changing the Event’s date, time, recurrence, or calendar does not rewrite the Task’s subtasks. Subtask completion belongs to the selected linked Task occurrence. In the current mobile and web Task flows, completing the final unfinished subtask can also complete the parent linked Task, and reopening a subtask can reopen a completed parent. Harmonise coordinates the parent linked Task status separately from the individual subtask change. This does not complete, reopen, or otherwise change the Event. Another linked Task occurrence remains unchanged. Completing the parent linked Task may also mark its subtasks complete where the current platform flow supports it. Use the parent linked Task completion control when you want to complete or reopen the whole Task directly.

Attachments

Task attachments remain attached to the Task or recurring Task series; they are separate from any attachments on the Event. A linked standalone Task or Task series can have up to five attachment slots, and the files are currently private to the Task owner.

For a recurring Event-linked Task, occurrences share the Task series attachment collection. The Event attachment choices above control which Event occurrences receive linked Tasks; they do not copy the Task’s files to each Event occurrence.

Files require an internet connection to upload or update. A file becomes available after it finishes processing successfully. See Recurring Tasks for how Task-series attachments behave when the Task is split, made standalone, or removed.

Completing or deleting linked Tasks

Completing a linked Task does not complete the Event. The Event also does not automatically complete the Task when its time passes.

Deleting the Task does not delete the Event.

For a Task that follows a recurring Event, the following actions apply only to This task:

completing or reopening it;
Task status, taken-by state, and sort order;
subtask completion;
adding, changing, or clearing Scheduled Date or Scheduled Date and Time; and
scheduled-start reminders.

Reusable Task details, such as title, description or notes, estimated duration, deadline reminders, or subtask definitions, can use wider Task mutation scopes where that edit permits them. These Task scopes are different from the Event attachment choices used when the Task is first added to a recurring Event.

Unlink a Task

When you unlink a Task, it becomes a standalone, non-recurring Task. It keeps its title, description or notes, estimated duration, subtasks, completion state, last Event-aligned timezone, Scheduled Date or Scheduled Date and Time, and scheduled-start reminders. It also keeps the Event-controlled deadline as its own Due Date:

an exact Due Date and Time for a timed Event; or
a date-only Due Date for an all-day Event’s first local date.

No future Tasks are generated from the former Event recurrence. Deadline reminders that remain valid become reminders for the preserved standalone Due Date. The Task stays in the same calendar, which it now owns independently.

If Event recurrence is explicitly removed, linked Tasks in the affected Event range are deleted instead. To retain one, unlink it before removing the Event recurrence. The same rule applies when an Event is deleted: only Tasks whose Event link is still present when deletion begins are deleted. A Task detached or unlinked beforehand is standalone and remains.

Offline and synchronization behavior

Harmonise can save some eligible core Task changes locally and synchronize them later. Eligibility can depend on the platform, local Task persistence, the calendar, the mutation scope, recurrence identity, synchronization state, and whether the operation has server-owned side effects.

Files, some Event-link or unlink changes, some recurring-series structural changes, provider-owned calendar actions, and other server-owned operations may require a connection. Do not assume that every linked Task change works offline. See Sync and offline use.

Common problems

I cannot choose a calendar

A linked Task uses the Event’s calendar. The calendar may be shown as From linked event instead of being independently selectable. An existing Task must already use that calendar before it can be linked.

The Task has the wrong timezone

The Event has one immutable timezone. Linking or relinking aligns the Task’s stored timezone with it; the linked Task does not offer an independent timezone choice. Ordinary Event movement does not change the Event timezone. Unlink the Task only when you want it to become standalone and preserve the last Event-aligned timezone.

The Task has the wrong effective deadline

For a timed Event, check the Event’s start date and time. For an all-day Event, check its first local Event date. That is the Task’s effective deadline while it remains linked.

The Task is scheduled after the Event deadline

That is allowed. Moving the Event changes the effective deadline and eligible deadline reminders, but not the Task’s Scheduled Date, Scheduled Date and Time, or scheduled-start reminders. Harmonise may show a non-blocking warning; saving is not blocked.

The Task did not appear on earlier Events

Check which Event attachment choice you used:

This event only adds the Task only to the selected Event.
This and future events starts from the selected Event and excludes earlier Events.
Entire series includes every eligible Event in the series, including eligible earlier Events.

I want to preserve a linked Task before changing the Event

Unlink the Task before deleting the Event or explicitly removing its recurrence. Tasks that remain linked when those operations begin are deleted; an unlinked Task becomes a standalone Task and remains.