Time windows vs due dates: which one your tasks need
A due date works for tasks with no real start constraint, like "renew car registration sometime this month." A time window, with both an earliest start and a deadline, works for tasks tied to a real clock, like a 2pm call or a medication dose, because it tells you when to begin, not only when to finish.
Two different questions, one due date field
Most task apps ask a single question about time: when is this due? That question is useful for some tasks and actively unhelpful for others. A due date answers "what is the latest this can happen." It does not answer "when should I actually start," and for a large share of ADHD task failures, the start question is the one that mattered.
What a due date is good for
Due dates work cleanly for tasks with genuine flexibility in when you do them, as long as they get done by a certain point. Renewing a library book due back in two weeks, filing an expense report due at the end of the month, or replying to a non-urgent email are all fine as plain deadlines. There is no wrong hour to do them, only a wrong day to have skipped past.
These tasks share one feature worth naming: nothing outside your own schedule constrains them. No business has to be open, no other person has to be available, no location has to be reachable. Whenever you decide to do them is, by definition, a valid time, which is exactly what makes a single deadline sufficient.
What a due date quietly breaks
The trouble starts when a due date gets attached to a task that actually needs to begin at a specific point, not just finish by one. A 2pm phone call has a due date of 2pm in most apps, but the task does not become possible to start until 2pm either, since businesses are not always open earlier and the call has to happen in that hour. If the app can only show "due 2pm," you get one alert, at 2pm, with no lead time to prepare or with a call that opens and closes in the same instant on your screen.
What a time window adds
A time window is a due date with a starting gate attached. The task stays quiet until its earliest start time, then reminders begin inside the window and get firmer as the deadline gets close. Say the task is picking up a prescription that is ready after 1pm and the pharmacy closes at 6pm. A due date of 6pm alone tells you almost nothing useful before 5:45. A window from 1pm to 6pm tells you the task became possible at 1, gives you the whole afternoon to fit it in, and only escalates as 6pm actually approaches.
The difference is small on paper and large in practice. A single deadline treats the whole day before it as equally irrelevant, right up until the last hour. A window treats the opening moment as information too, which is often the piece that actually changes whether a task gets done with room to spare or gets missed by six minutes.
A quick way to sort your list
Go through your current list and ask one question per task: "does it matter when I start this, not just when I finish it." If the answer is no, a due date is enough, and adding a window would be extra structure with no payoff. If the answer is yes, because of business hours, another person's availability, or a physical location, that task needs a window: an earliest start plus a deadline, set directly on the task rather than guessed from the words in its title.
- "Pay the electric bill" (due by the 15th, no earlier constraint): due date
- "Pick up prescription" (ready at 1pm, pharmacy closes at 6pm): window, 1pm to 6pm
- "Call the insurance company" (only open 9 to 5): window, 9am to 5pm
- "Send the thank you card" (no real constraint): due date
Setting this up without overthinking it
You do not need to sort your whole list at once, and trying to reclassify every task in one sitting tends to stall before it finishes. The tasks worth converting to windows first are the ones that have already caused a problem: the call you missed because it closed by the time you noticed the reminder, the pickup you forgot was time-limited. In Drifta, any task's schedule is set on its edit screen, where you can add a start time, a deadline, or both, and the task stays silent until that window opens rather than sending a reminder the moment it is created.
For more on getting the start time right, see why every task needs an earliest start time, and for the version of this problem specific to errands with limited hours, reminders for errands that only work during business hours.
Common questions
Can a task have both a due date and a time window?
In most task systems these overlap rather than combine, since a time window already includes a deadline. The practical choice is whether a task also needs an earliest start time attached to that deadline, which turns a plain due date into a window.
What happens if I give every task a time window?
Windows work best reserved for tasks where timing genuinely matters. Applying one to everything, including flexible tasks like "read that article," adds false urgency and trains you to ignore windows generally, which defeats the purpose for the tasks that actually need one.
Why do due dates alone lead to last minute work?
A due date only tells you the latest acceptable moment, so without a separate start signal, the task naturally gets attempted right before that moment. Nothing marks an earlier point where starting would have been reasonable, so nothing pulls you to start earlier.
This article shares practical organizing ideas. It is not medical advice. For diagnosis or treatment questions, talk with a qualified clinician.