Count overnights and hours across a real calendar
Set the period, tick which nights of the repeating two-week cycle belong to Parent A (the rest belong to Parent B), add holiday overrides where the pattern changes, and this calculator expands the schedule across the actual calendar, leap years included, and returns each parent’s overnights, percentages, and a month-by-month table. Count by overnights, or by hours with your real exchange time. It counts time; it does not interpret orders, and the legal limits section below the results explains where counting stops and law begins.
Disclaimer: This calculator gives estimates for general information only. It is not financial, medical or other professional advice, and it is not legal advice. Parenting-time percentages can carry legal and support consequences that depend on your jurisdiction and your order; a family lawyer or your court reads those, not this page.
What this calculator does
Most parenting-time disputes about numbers are really disputes about counting: which nights, over what period, under which convention. This tool removes the arithmetic from the argument. A repeating 14-day pattern is laid over the real calendar between your two dates, so February in a leap year counts its 29 days and a period that starts mid-cycle counts what it actually contains. Overrides then replace the pattern for the dates they cover (school holidays, trips, exceptions), nights caught by two overrides are flagged rather than silently double-decided, and the totals are divided by the total eligible time in the period, which is the only denominator a percentage can honestly use.
How to use it
- Anchor the cycle on a date you are sure of. Night 1 is the period start, so start the period on a known pattern day (the first day of a rotation you can verify) or the whole expansion shifts by that error.
- Choose the convention your order uses. Orders and guidelines variously count overnights or hours, and the two give different percentages for the same family. The hours mode exists because an 18:00 exchange quietly moves a quarter of every “night” to the other parent.
- Put holidays in as overrides, not pattern edits. A pattern is the ordinary rhythm; a two-week summer block is an exception. Keeping them separate is what makes the totals explainable to the other parent, a mediator or a court.
- Use a full year for a fair percentage. Short periods overweight whichever parent holds the holidays inside them. A calendar year (or the school year, stated as such) is the period most guidelines and most people mean.
The method
- Expansion: each date in the period takes the owner of its position in the 14-day cycle (position counted from the period start).
- Overrides: applied in order over the pattern; a date covered by two or more overrides takes the last one covering it and is counted in the overlap flag.
- Overnights: each date counts wholly to its owner. Hours: each date’s owner holds the child from the exchange time that day to the exchange time the next; the period’s first partial segment (midnight to the first exchange) is credited to the first night’s owner and flagged as assumed.
- Percentages: each parent’s total divided by the total time in the period, times 100. Legal child-support formulas are a separate machinery and are not used here.
Worked examples
The fortnight. A period of 1 to 14 January 2026 with Parent A ticked for nights 1 to 4 of the cycle: Parent A has 4 overnights (28.57%) and Parent B has 10 (71.43%). Add an override giving 2 and 3 January to Parent B (a trip, say) and the same period reads A 2 (14.29%), B 12: two nights moved, and the percentage moved by exactly their weight, which is the sanity check every result here can pass.
The leap February. February 2028 has 29 days. With A ticked for the first seven nights of each cycle, the month expands to A 15, B 14: two full cycles of seven each, plus the 29th day landing on cycle position 1, an A night. A calculator that assumed 28 days, or 30, would miss the night that makes the month.
Reading your results
Read the month table before the headline percentage: it shows where time concentrates, and a fair-looking year can hide a lopsided season that matters to a child even when the totals balance. Read the overlap flag as a to-do: two overrides claiming the same night is a real schedule conflict to resolve with the other parent, not a rounding artefact. And read overnights against hours if your situation sits near a threshold: the same arrangement can honestly be 28.57 percent of nights and a different share of hours, and which one applies is a property of your order, not of the arithmetic.
Limitations and legal limits
- This page counts time. It does not interpret your order. What counts as an overnight, whose holiday wins, and what a percentage triggers in support are set by your jurisdiction’s law and your specific order or agreement, which override any general counting here.
- Guideline thresholds are jurisdiction-specific. Some places attach support adjustments to overnight thresholds; the thresholds, and even whether overnights or hours count, differ by state, province and country. Nothing on this page states yours.
- The pattern is a rhythm, not a life. Sick days, swaps and one-off changes accumulate outside any pattern; the override slots model the planned exceptions, and a year of actuals would need the actual calendar kept.
- Hours mode has one stated assumption. The first partial segment of the period is credited to the first night’s parent because the previous night sits outside the period; over a long period the effect is a few hours, and it is flagged in the results rather than hidden.
Frequently asked questions
What counts as an overnight?
In the overnight convention used here, the parent at whose home the child sleeps that night. It is the most common counting convention because it is observable and simple, but it is not universal: some orders and guidelines count hours, some count days by a stated hour, and a few define the overnight by where the child wakes. Your order’s definition governs, and the hours mode exists for the orders that count that way.
Why does the percentage change between overnights and hours?
Because an exchange at 18:00 means the “night” parent’s day includes the previous evening and the next parent’s day starts at dinner. Across a period, evening hours accumulate to the parent whose nights follow them, and the shares shift by real amounts. Neither figure is the true one in the abstract; each is the true one under its convention, which is why the tool asks which convention you are counting under instead of deciding for you.
How should holidays be shared in the count?
Exactly as your arrangement states them: enter each holiday block as an override to the parent who holds it. Alternating holidays (one parent this year, the other next) is the common pattern, and counting two consecutive years is the honest way to show its balance, since a single year will always look one-sided. The month table makes the seasonal weight of holidays visible rather than arguable.
Can I use this for a child support calculation?
You can use its totals as the time input a support guideline asks for, and no further. Support formulas combine parenting time with incomes, costs and jurisdiction-specific adjustments, and several draw lines at particular percentages, so the figure that matters legally is the one your jurisdiction’s own calculator or a lawyer produces from these totals. This page’s disclaimer is not boilerplate on that point; it is the boundary of what counting can do.
Related calculators
Method: recurring 14-day pattern expanded over actual calendar dates (UTC-safe date arithmetic, leap years included), ordered overrides with overlap flagging, percentages over total eligible time in the period. Last reviewed: 15 October 2026.