Fixed-time reminders work well for most people. You set your medications for 8am, 12pm and 6pm and the app reminds you at those times every day. For the majority of medications and routines, that is exactly the right approach.

But some people need something different. Not because fixed reminders are flawed, but because certain medications and certain lifestyles call for a different kind of scheduling. That is why we built interval dosing.

When fixed times are not enough

Some medications are prescribed with instructions like "every 4 to 6 hours" rather than at specific clock times. Pain medications, certain antibiotics and some neurological drugs fall into this category. The goal is even spacing throughout your waking hours, not alignment with a particular hour on the clock.

For people with consistent routines, setting fixed times that happen to be four hours apart works fine. But for shift workers, people with conditions that affect sleep, or anyone whose wake time varies significantly from day to day, those fixed times can drift out of sync with their actual day.

A nurse who works rotating shifts might wake at 5am one week and 2pm the next. A parent of a newborn might not have a predictable wake time at all. Someone with a condition that disrupts sleep might start their day at 7am on Tuesday and noon on Thursday. In these situations, a reminder at 8am is sometimes perfectly timed and sometimes hours too early or too late.

These users asked us for a way to anchor their medication schedule to when their day actually starts. (If your schedule is consistent but you are taking several medications with different timing requirements, see our guide on managing multiple medications.)

How interval dosing works

Interval dosing is an upcoming scheduling option in Cadence that will sit alongside the existing fixed-time reminders. When you set up a medication, you will have two choices:

  • Fixed times -- the default. You pick specific hours and get reminded at those times every day. This is ideal for most medications and most routines.
  • Interval dosing -- you set the number of hours between doses and a daily maximum. Each day, you take your first dose whenever you are ready and the app schedules the rest from that point.

The two modes can be mixed. You might have one medication on a fixed 8am schedule and another on a 4-hour interval. They both appear on the same Today screen, contribute to the same streak and are tracked in the same adherence data.

A typical day with interval dosing

You wake up and open Cadence. Your fixed-time medications show their usual schedule. Your interval medication shows a "Take First Dose" card.

You tap it at 9am. Cadence now knows your day has started and schedules reminders at 1pm, 5pm and 9pm (assuming a 4-hour interval with 4 daily doses). If you had woken at 7am instead, the reminders would have been at 11am, 3pm and 7pm. The spacing stays consistent; the clock times adapt.

Each reminder is only scheduled after you confirm the previous dose. You are never stacking up notifications for future doses that are not relevant yet.

Who benefits from this

Interval dosing is useful for a specific set of situations:

  • Shift workers whose "morning" changes from week to week
  • People with conditions that affect sleep patterns whose wake times vary day to day
  • Parents of young children who sleep in fragments
  • Anyone on medications prescribed as "every N hours" rather than at fixed times
  • People recovering from surgery or illness with temporarily disrupted routines

For everyone else, fixed-time reminders remain the simpler and better option. We are not replacing anything -- just adding flexibility where it is needed.

Setting it up

When you add or edit a medication in Cadence, the Schedule section will include an "Interval Dosing" toggle. Turn it on and you will see three settings:

  • Dose interval -- how many hours between doses (1 to 12)
  • Maximum doses per day -- a safety cap for the number of doses generated
  • First dose reminder -- an optional nudge at a time you choose, in case you forget to open the app

Once configured, the medication will appear on your Today tab with a "Take First Dose" card each morning. Tap it when you are ready. The rest follows automatically.

How it works with streaks and adherence

If you do not take the anchor dose on a given day, that day has zero scheduled doses and does not break your streak. We chose this approach because interval dosing is used by people with unpredictable schedules, and penalising a day where the chain was never started would be counterproductive.

Once you do take the anchor dose, all subsequent interval doses are tracked normally. If you take the first dose but miss the third, that is reflected in your adherence percentage just like any other missed dose. For more on why medication adherence matters and how streaks help you stay consistent, see our guide on building a medication habit.

What is next

We are considering a few refinements:

  • Automatic anchor detection using HealthKit wake data instead of requiring a manual tap
  • Minimum spacing for as-needed medications -- "take when needed but no sooner than every 4 hours"

If either of these would be useful, let us know through the support page.

Coming in the next update

Interval dosing is coming to Cadence in an upcoming release. When it lands, you will find the "Interval Dosing" toggle in the Schedule section when adding or editing a medication.