This is a thorough walkthrough of everything Duonidus can do, with concrete examples along the way. Jump straight to a section using the list below, or read it all the way through. If you'd rather start from scratch, one click at a time — with every way to take, take over and give away days — use the step-by-step guide.
Every way to take, take over and give away days — and how to make notes and repeating notes — explained from scratch, one click at a time.
Open the step-by-step guideCreate an account, then invite the other parent to join your shared calendar. You both need to be signed up before the calendar can be used to split days between you — until then, you'll see an invite link you can pass along.
Every date in the calendar is split into two halves: a morning half and an afternoon half, so a handover in the middle of the day can be arranged precisely. The afternoon of one date and the morning of the next belong together as one period — from handover to handover. Click a free half to take it: it and the connected half on the neighboring date immediately turn your color. Click again to release them. You can choose how wide each half is shown under Display settings.
How to read the calendar
A day never changes owner without the other parent saying yes. To take over a day the other parent has: double-click it, or press and hold it and choose “Request to take over this day”. A ⇄ then appears on the day, and the other parent can accept or decline. To give away a day — your own, or one nobody has taken yet: press and hold it and choose “Offer this day to the other parent”. This works in both locked and unlocked months. The period gets a bold border in the other parent's color, shaped like a C pointing towards the neighboring date, because the two halves belong together. The day only changes owner when the other parent presses and holds it and chooses “Accept the takeover of this day” — they can also choose “Decline the offer”, and you can undo it yourself with “Cancel offer”. In a locked month you can also double-click your own day to offer it. Dialog boxes can be dragged out of the way using the move icon in their corner. The step-by-step guide shows every scenario, one click at a time.
Experiment freely below — nothing is saved, so you can't do anything wrong. Use Previous/Next to go through the three steps.
Press and hold a date to write a note on it — handy for handovers, birthdays or anything else you need to remember. Notes appear as an envelope in the calendar: click it to open the note, or turn on “Show notes” to see the text directly in the cells. If you write e.g. “birthday” in Danish (“fødselsdag”) or “hike” (“vandretur”), the note gets its own icon (🎂 or 🏕️). In the same dialog you can write a private note only you can see (blue envelope with a lock). Tap 🔁 “Repeat note” to make the note recur every week or every 2 weeks until a chosen end date. If you later edit or delete a repeating note, you are asked whether it applies to that note only or to all following ones too. With a paid add-on you can give notes colored categories, e.g. “school” and “activities”.
Once you've agreed on a month's schedule, one of you can propose locking it: click the padlock at the top and choose “Month lock”. The other parent must accept before the month is locked. In a locked month, days can't be taken or released with a click — only through requests and offers the other parent has to agree to. Unlocking also requires both of you to accept. Under the same padlock you'll find “Note lock”: a long press then doesn't open notes, so you don't trigger it by accident on your phone. The note lock only applies to the device you turn it on for.
Under “Planning” you can set up a 14-day repeating pattern (e.g. “one week with each parent”) and apply it to a whole period at once instead of clicking every day by hand. Individual weeks can be excluded from the pattern, e.g. holidays. There is a matching note pattern for fixed notes over a period. If there are conflicts with days already taken, you can choose to skip them or cancel the whole operation. You can also reset the days in a period — this requires the other parent's acceptance — and reset the notes in a period.
You choose how wide the morning and afternoon halves appear in your own calendar view: “Full day” shows the whole field as one color based on who has the evening, “25/75” makes the morning half narrower, and “50/50” (default) splits it evenly. This setting is personal — it only affects your own view, not the other parent's.
There are 17 color themes. Without the add-on you can switch between three fixed themes directly in the calendar. With a paid add-on you choose your own 3 favorites among all 17 under “My profile”, and you can use the dice button to get a random theme.
The statistics page shows how many days each of you has had — in total, per year, and per month — so you can easily keep track of whether the split is what you intended.
Under “Communication” you'll find a shared chat, a handover list and a shared note you can both edit. In the chat you can reply to a specific message, react with 👍, ❤️ or 👎 and delete your own messages, and links are clickable. With a paid add-on you can send pictures via 📎. The handover list can be shown as your list, the other parent's list or a combined list, it can be sorted in several ways, and you can both tick items off.
You can create a read-only link that, say, grandparents can use to follow the calendar without being able to change anything. You'll find and manage the link under “My profile”.
With a paid add-on you can subscribe to a personal calendar feed (ICS) that keeps your phone's own calendar app updated automatically. The feed link is personal and shouldn't be shared. Without the add-on you can also import events from Google Calendar as notes under “My profile”.
Most of Duonidus is free. A paid add-on gives you: free choice of 3 color themes among all 17 and a random theme, note categories, a calendar feed (ICS) for your phone's calendar, pictures in the chat and notifications on your phone. The subscription is handled via PayPal and can be cancelled at any time under “My profile”.
Under “My profile” you can change language, update your name, e-mail and password, choose display settings, see the history of changes in the calendar and open the list view. Under “Privacy” you can download an export of all your data or read how it is used. At the bottom of the profile page you can delete your account.
Duonidus can notify you on your phone when the other parent asks to take over a day, wants to give a day to you, or offers you an unclaimed day. Every evening at 9 pm you also get a short reminder if there are unanswered requests from the other parent or unread messages in the chat — if nothing is outstanding, nothing is sent. Notifications are part of the paid add-on and are turned on separately for each device under “My profile”.
How to turn them on on an iPhone
Notifications not showing up?
On Android and computers, notifications work directly in the browser (e.g. Chrome, Edge or Firefox) — just turn them on under “My profile”.
The list view shows the calendar as one long list you can scroll up and down: one horizontal bar per day in the color of the parent who has it, with notes shown in full. Open it from the “List view” box under “My profile”. It is read-only — changes are made in the calendar.