Deferred todos (t:)

Overview

Todo.txt format does not specify standard way of deferring tasks. However many todo.txt tools support this functionality as an extension relying on t attribute. Simpletask and topydo may serve here as examples.

Abbreviation t comes probably from visibility threshold date. It's purpose is to keep entries hidden until a specified date in the future.

Defer date may be defined as a date assigned to an item that you don’t want to (or can’t) consider for completion until later.

Examples

One-offs

Deferred items may be used for one-off tasks or reminders to keep things off your mind. They may give you nudge of attention well in advance of any due dates.

2021-07-12 decide about changing insurance company t:2021-09-15
2021-07-12 consider: starting project XYZ t:2021-07-25

Recurrence

Similarly to due dates, deferred items may specify recurrence intervals. (See Recurring-todos for rec: syntax). This helps you automate maintenance of items in your todo.txt system that reoccur in your life on some regular basis.

By default non-strict recurrence is used meaning that recurrence interval is added to the date of completion.

Repeated items may pop-up frequently helping you create habits or infrequently keeping your list clean from items that are only occasionally relevant.

2021-07-12 Perform morning routine t:2021-07-13 rec:1d
2021-07-12 Water plants t:2021-07-19 rec:7d
2021-07-12 Get Car Inspected t:2022-06-01 rec:18m

You can also define strict recurrence in which case interval is added to assigned date.

2021-07-12 perform weekly review t:2021-07-16 rec:+7d
2021-07-12 Renew car insurance t:2021-05-15 rec:+1y

Recurrence with due dates

Sleek allows combining defer dates with due dates. strict and non-strict cases are deliberately handled differently. Note however that other todo.txt tools may have this logic implemented differently or not implemented at all.

Strict-mode

For strict mode recurrence interval is added to due and threshold dates.

Example: "taxes submission is due on 30th April each year, item should become visible one month in advance"

Translates into

2021-01-01 taxes are due in a month t:2021-03-30 due:2021-04-30 rec:+1y

Completing this item on 2021-04-15 results in:

    x 2021-04-15 2021-01-01 taxes are due in a month t:2021-03-30 due:2021-04-30 rec:+1y
    2021-04-15 taxes are due in a month t:2022-03-30 due:2022-04-30 rec:+1y

Non-strict mode

For non-strict mode there's some intricacy:

• due and t are first used to calculate number of days between the date task should appear on the list and the date it's due
• due is incremented by recurrence interval
• t is updated with value that preserves initial window between t and due

Example: "Home plants need watering about once a week. They would probably rot if they were watered too often - 4 days seems like a safe interval. It's likely that they would start to wither after 2 weeks without water."

In other words, there's 10 day watering window and I'd like to schedule next due date with 2 week interval.

Translated into todo.txt entry

2021-07-05 Water plants @home +quick due:2021-07-19 t:2021-07-09 rec:14d

Completing this item on 2021-07-13 results in:

    x 2021-07-13 2021-07-05 Water plants @home +quick due:2021-07-19 t:2021-07-09 rec:14d
    2021-07-13 Water plants @home +quick due:2021-07-27 t:2021-07-17 rec:14d

Other terms and GTD

In some places visibility threshold date / t may be referred to as start date or tickler date. This is somewhat inaccurate:

• start date, do date or schedule date imply a "day-specific action" (using GTD vocabulary - things you need to do sometime on a certain day, but not necessarily at a specific time)
• tickler implies a "day-specific information" (using GTD vocabulary - information that may be useful on a certain date)

It may well happen that deferred item gets completed (do date) the same day it was deferred to, or that information was "consumed" (tickler) and removed from the list on that date. Similarly visibility threshold date / defer date may coincide with due date, but those concepts are different. Deferred item may stay visible on the list for multiple days until eventually get's completed/further deferred or deleted.

Deferred items are quite versatile meaning they may be a good fit for entries that would otherwise live in other parts of GTD system - calendar, tickler, someday/maybe, next actions context lists, project list and checklists.

There's no explicit support for schedule date in todo.txt.