How Daylight Saving Time Disrupts Remote Teams

Most people know that clocks change twice a year. What fewer people realise is that different countries change them on different days — and during the gap between those dates, every standing meeting you've booked with a colleague in a different country is off by an hour.

For remote teams spread across the US, the UK, and continental Europe, this is one of the most predictable sources of missed calls, late arrivals, and confused calendar invites of the entire year. It happens every spring and every autumn, at almost exactly the same time. And it's completely avoidable once you know what's coming.

Why clocks don't all change on the same day

Daylight saving time is a country-by-country decision, not a global rule. Each country sets its own start and end dates, and those dates don't align across borders — even between countries that are geographically close.

In the United States, clocks move forward on the second Sunday in March and back on the first Sunday in November. In the United Kingdom and most of the European Union, the change happens on the last Sunday in March and the last Sunday in October. In the southern hemisphere — Australia, New Zealand, South Africa's summer — the dates are flipped entirely, because the seasons run in reverse.

The result is that twice a year, there's a window of roughly two to three weeks during which the US has changed its clocks but the UK and EU have not (or vice versa). During those weeks, the time difference between, say, New York and London is one hour different from what it normally is.

The spring mismatch window

In March, the US springs forward first — typically around the second weekend of the month. The UK and EU follow roughly two to three weeks later, on the last Sunday of March.

During those two to three weeks, the usual five-hour gap between New York and London shrinks to four hours. A standing Monday 3 PM London call, which normally reaches New York at 10 AM, now arrives at 11 AM Eastern. If your calendar is set to repeat weekly and nobody has re-checked the conversion, people will be joining at the wrong time.

The same shift ripples through any pairing that involves one country that's already moved and one that hasn't yet. London–Paris, which is normally one hour apart, stays the same because both are in the EU and move together. But New York–Paris, New York–Berlin, New York–Amsterdam — all change during that window.

The autumn mismatch window

In autumn, the UK and EU move back at the end of October. The US follows roughly a week later, at the start of November.

During this one-week gap, London has already fallen back an hour but New York has not. The normal five-hour gap between them temporarily becomes six hours. A 4 PM London call that a New York colleague normally joins at 11 AM now shows up in their calendar at 10 AM — or 12 PM, depending on which direction the confusion goes and who recalculated and who didn't.

The autumn window is shorter than the spring one, but it still catches teams out every year.

Countries that never change at all

A complicating factor is that not all countries observe daylight saving time. Japan, China, India, Singapore, South Korea, and most of the Middle East run on a fixed offset year-round. Most of Africa and large parts of South America do not change either.

For teams with colleagues in these countries, the mismatch window is even longer and less predictable — their offset doesn't move, but their US or European colleagues' offsets do. A Mumbai–London call that is normally 4.5 hours apart becomes 5.5 hours apart when the UK shifts to BST in late March. And it shifts back when the UK returns to GMT in late October.

Within the United States, most of Arizona (apart from the Navajo Nation) also doesn't observe daylight saving. This means Arizona's offset relative to New York and Los Angeles changes twice a year — even though Arizona's clocks never move.

What this means for standing meetings

The practical impact on remote teams is straightforward: any recurring meeting that spans countries in different DST regimes will shift by an hour for some participants during the mismatch windows. The meeting time won't look wrong in your own calendar — your device converts it to your local time correctly. But it will look wrong to the person on the other end if they're still mentally using the old conversion.

The most common symptom is the "hour early or late" confusion. Someone joins a call 60 minutes before anyone else appears; someone else messages the group asking if the meeting is still happening. Occasionally a participant simply misses it entirely.

Three rules that prevent the confusion

1. Always specify a city, not a time zone name. "Let's meet at 3 PM ET" is ambiguous when ET can mean either EST (UTC-5) or EDT (UTC-4) depending on the time of year. "Let's meet at 3 PM New York time" is unambiguous — you look up what New York is doing that day, and the correct local time in London follows automatically.

2. Double-check recurring meetings in the two weeks around the changeover dates. Set a calendar reminder for mid-March, late March, late October, and early November. Use a live converter — like ZoneKit's Time Zone Converter — to verify what 3 PM in one city actually is in the other on that specific date. A date-aware converter handles this automatically; a static "5-hour difference" calculation doesn't.

3. If your team spans different DST regimes, use UTC anchoring for the most critical meetings. Agreeing that "the Monday call is always 14:00 UTC" means everyone can convert from one fixed reference point rather than from each other's shifting local times. This is how aviation, financial markets, and international science have handled the problem for decades.

Try the tools

ZoneKit's Meeting Planner shows a colour-coded grid of working hours for multiple cities side by side, using live DST-aware calculations — so the window it highlights as working hours for everyone is always correct for the specific date you're looking at, including during mismatch weeks. The Time Zone Converter lets you check a specific time on a specific date to verify what it will be in each city, including any DST adjustment that applies that day.

More ZoneKit guides

• The remote worker's complete guide to working across time zones
• GMT vs UTC: what's the difference?
• What is UTC? A plain-English guide
• Time difference between London and New York
• Time difference between London and Sydney