Daylight Saving Time and Your Parenting Plan: The Missing Hour

Most parenting plans contain a line like "exchange shall occur each Sunday at 6:00 p.m." It sounds equal. It is equal — eleven months a year. Twice a year, daylight saving time silently bends that handoff. On one Sunday in spring, that day is only 23 hours long, so the custody week that ends on it runs 167 hours instead of 168. On one Sunday in fall, the day runs 25 hours and that week 169. If you, your co-parent, or a court ever look at percentage of parenting time, those two hours show up in the numbers — and the plan on paper stops matching the reality your tracker records.

This isn't a tracking bug. It's a wording problem in the plan itself. Here's exactly what happens, why it matters, and the four-line addendum that closes the gap.

How DST quietly bends your handoff

On the second Sunday of March in the United States (last Sunday of March in the EU), the clock jumps from 2:00 a.m. straight to 3:00 a.m. The calendar still shows a 24-hour day, but only 23 hours of actual time pass. Because the clock moves at 2:00 a.m., the missing hour falls inside the week that ends at that Sunday's 6:00 p.m. handoff: that week runs 167 hours instead of 168, so the parent finishing it is an hour short. The parent who picks up at 6:00 p.m. gets a normal 168-hour week.

On the first Sunday of November in the U.S. (last Sunday of October in the EU), the reverse happens. The clock falls back from 2:00 a.m. to 1:00 a.m. That Sunday has 25 actual hours, and again the change lands inside the week that ends at that Sunday's handoff: 169 hours instead of 168. The parent finishing that week gains an hour; the one taking over gets a normal week.

It's about a one-hour swing per transition. What matters is whose week each transition lands in. If the same parent has both transition weeks, the two cancel out — 167 plus 169 hours is exactly two normal weeks. If they land in different parents' weeks, one parent ends the year an hour short and the other an hour long: a two-hour spread between what the plan says on paper and what the clock actually did.

Where the gap actually shows up

For most families, this is invisible. The exchange happens at 6:00 p.m. regardless of what the clock looked like at 2 a.m. Life moves on. But three places treat parenting time as numbers, and that's where the gap shows up.

1. Child-support and parenting-time percentages.

The Income Shares model used by most U.S. states (and the equivalents in Germany, France, and Brazil) weights support payments by the share of time each parent has with the child. A signed plan that says "50/50" and a tracker that says 49.96% / 50.04% are technically consistent — but in a disputed case, that's the kind of detail opposing counsel uses to argue the records are sloppy. Documenting the DST drift, instead of pretending it isn't there, makes the numbers defensible.

2. Tax claims that depend on overnights.

Good news here: the U.S. IRS rule for the dependent child uses nights, counted using IRS Form 8332 worksheets. DST doesn't change the number of bedtimes — there's still one going-down and one waking-up per kid per day. Spring forward doesn't cost you a Child Tax Credit. Fall back doesn't hand one to the other parent. Tax-credit math is safe.

3. Parenting-time apps that count actual hours.

Trackers that log the actual start and end of each parent's custody window — with timestamped, hour-level records — will correctly capture the 167-hour week and the 169-hour week. Trackers that only count "days had" round both weeks to seven and silently lose the data. If you might ever need to explain those totals, the hour-accurate version is the one you want. (Our guide on how to track custody days effectively walks through the difference.)

Why most parenting plans get the wording wrong

Most plans we've seen contain phrases like "exchange shall occur each Sunday at 6:00 p.m." That phrase is precise about clock time but silent about duration. On DST Sundays, the duration silently changes. A smaller subset of plans go further and say "every seven days, starting Sunday at 6:00 p.m." — which is actually worse, because seven days post-transition is 167 hours (spring) or 169 hours (fall), and the next handoff snaps right back to "Sunday 6:00 p.m." the following week. The shift is real; the plan just doesn't describe it.

The cleanest plans we've seen do one of three things: anchor handoff times to local clock time and explicitly say DST drift is zero-sum over the year; use UTC offsets (rare, mostly in cross-border or military families); or include a one-hour makeup clause at the next regularly scheduled exchange after each transition.

The four-line addendum that closes the gap

You don't need to renegotiate the whole plan to fix this. One addendum, signed and dated, is enough. Here's a template that covers the common cases:

DST and Time-Zone Clause. All exchange times in this plan are local clock times in [STATE / country]. On the days each year when daylight saving time begins or ends, any one-hour gap or duplicate hour resulting from the clock change shall be borne equally over the calendar year — the affected hour shall be made up at the next regularly scheduled exchange, or noted in a shared log for annual reconciliation. If either parent relocates such that the child crosses time zones for an exchange, exchange times shall be specified in the time zone of the receiving parent.

That language anchors handoff times, defines what happens on transition days, and gives a rule for cross-time-zone moves. It's short, neutral, and easy to get agreement on, because it doesn't advantage either parent over the year.

This is general information, not legal advice. If you're in active mediation or litigation, run any addendum past your attorney first.

What to do today

Three practical steps for the next month:

1. Check the spring and fall transition dates for your jurisdiction. In the U.S., mark the second Sunday of March and the first Sunday of November. In the EU, mark the last Sunday of March and the last Sunday of October. Brazil ended national DST in 2019 — but if your co-parent lives in a DST-observing country, the gap still affects you.
2. Look at what your tracker is actually counting. Is it logging actual elapsed hours between exchanges, or just "days had"? If it rounds to days, your hour totals will read 50/50 even in years they shouldn't. A custody calendar that logs each handoff to the hour is the one you want for any number you might need to show your lawyer or mediator.
3. Send one message to your co-parent. Something like: "Just realized DST creates a small hour gap in our handoff schedule twice a year. Want to add a one-line clause that we split it evenly over the year? Doesn't change anything practical — just makes our hour totals match the plan." Save the exchange. (If you're thinking about wording, our notes on co-parenting communication that holds up are worth a read.)

None of this is about the hour itself. It's about the gap between what your parenting plan promises and what your tracker records. Closing that gap costs four lines.