Most separating parents choose a schedule under time pressure, from a list of names that mean nothing yet. Then they run it for a term and discover the problem was never the ratio of nights. It was the number of handovers, or the length of the gap, or the fact that the pattern cuts across a Wednesday sport commitment nobody thought about at the time.
Here is what actually separates the common patterns.
The three things that decide it
Handovers per fortnight. Every handover is a point of contact, and points of contact are where friction happens. They also cost time — two drives, two sets of bags, two children who need twenty minutes to settle. A pattern with six handovers a fortnight is not twice as much admin as one with three. It is closer to four times as much, once you count the re-settling.
Longest gap from either parent. This is the number that matters most for younger children, and the one parents underestimate. A seven-day gap is a long time for a five-year-old. It is unremarkable for a fifteen-year-old.
Whether it repeats weekly. Patterns that land on the same weekday every week are dramatically easier to live with. Sport, music, therapy and after-school care are all scheduled weekly, and a pattern that drifts against them generates a permanent low-grade coordination cost.
The patterns
Alternating weeks
Seven days with one parent, seven with the other.
Two handovers a fortnight — the lowest of any equal-time pattern — and it repeats perfectly against the school week. Each household gets long enough stretches to have a normal routine rather than a permanent visit.
The cost is the gap. Seven days without seeing a parent is the longest of the common patterns, and it is the reason this one is usually recommended for older children rather than pre-schoolers. Many families soften it with a midweek dinner or a scheduled call that does not change whose night it is.
2-2-3
Two nights, two nights, three nights, then it flips.
The shortest gaps of any equal-time pattern — a child is never more than three nights from either parent — which is why it is the standard recommendation for young children.
The cost is handovers: six a fortnight, three times what alternating weeks asks for. It also does not repeat weekly. Your Mondays alternate, so every weekly commitment needs checking against the pattern rather than being memorised. Families running 2-2-3 tend to be the ones who most need a shared calendar, because nobody holds this one in their head reliably.
2-2-5-5
Two, two, five, five.
A genuine middle option, and underrated. Each parent has the same two weekdays every single week — one has Mondays and Tuesdays, the other has Wednesdays and Thursdays, always — while the weekends alternate in five-day blocks. Weekly commitments become trivial to manage because the weekday assignment never moves.
Four handovers a fortnight, and a maximum gap of five nights. If alternating weeks feels too long and 2-2-3 feels too churny, this is usually the pattern being looked for.
3-4-4-3
Three, four, four, three.
Same fixed-weekday advantage as 2-2-5-5 and a shorter maximum gap of four nights, at the cost of four handovers a fortnight. It suits families who want short gaps but cannot absorb the handover load of 2-2-3.
Every weekend, and other unequal patterns
Not every family is splitting time evenly, and a schedule does not have to be equal to be workable. Weekdays with one parent and weekends with the other is simple, predictable and repeats perfectly — but it hands one parent all of the homework and none of the fun, which is worth naming out loud rather than discovering resentfully in year two.
What to do before you commit
Write the pattern out against an actual calendar for a full term, with the school terms and the public holidays on it, and look for what breaks. Most patterns fail on the same things: the Wednesday activity that lands in the wrong household half the time, the fortnight where a public holiday turns a three-day block into a six-day one, and the birthday that always falls in the same parent's week.
Then decide the holidays separately. Almost every family ends up overriding the base pattern for school holidays, Christmas and birthdays, and it is far easier to agree those rules once, in advance and in writing, than to negotiate them every year from a position of whoever remembered first.
Changing it later
Schedules are not permanent, and the right pattern for a four-year-old is rarely the right pattern for a fourteen-year-old. What matters is that a change is something you both actually decided, rather than a drift neither of you quite agreed to.
That is the part Halven makes easy. A schedule change is something one of you asks for and the other says yes or no to, and the calendar updates itself the moment they do — so nobody is working from a different version of what was agreed.