How to Schedule a Meeting Across Time Zones (Without DST Errors)

To schedule across time zones, convert each person’s working hours to one reference (usually UTC), pick a slot inside the overlap, and check the specific date — because the offset between two cities is not fixed when either of them observes daylight saving time. Then write the invite with an explicit zone, ideally with UTC alongside.

Calendar software handles the arithmetic once the event is created in the right zone. Most mistakes happen before that: when someone works out a “usual” difference in their head and applies it in a week when it does not hold.

Step 1: find the overlap

Take each participant’s working day, say 09:00 to 17:00 local, and convert it to a common reference. The overlap is whatever is left after intersecting the ranges. The time zone converter does this for any pair of cities, and the event planner lays out several cities’ hours side by side.

The four pairs below cover most real-world cases. Offsets are computed from the IANA time zone database for 2027 dates.

New York and London

Usual gap: 5 hours. New York is UTC−5 in winter and UTC−4 in summer; London is UTC+0 in winter and UTC+1 in summer.

New York	London	Notes
09:00	14:00	Start of the overlap
12:00	17:00	End of the overlap

The overlap is about three hours of the New York morning and London afternoon. It is the easiest of the four pairs.

London and Singapore

Singapore is UTC+8 all year. The gap is 8 hours when London is on GMT and 7 hours during British Summer Time.

Date	London	Singapore
13 Jan 2027	09:00	17:00
14 Jul 2027	09:00	16:00

The overlap is London’s early morning and Singapore’s late afternoon, and it is thin: with both sides keeping 09:00–17:00, there is one shared hour in summer and none in winter. In practice one side shifts slightly — a London 08:00 start is 16:00 in Singapore in winter.

San Francisco and Bangalore

India uses UTC+5:30 all year with no daylight saving; San Francisco is UTC−8 in winter and UTC−7 in summer. The gap is 13½ hours in winter and 12½ in summer, so a normal working day has no overlap at all. Someone has to work outside office hours.

Date	San Francisco	Bangalore
Wed 13 Jan 2027	Wed 08:00	Wed 21:30
Wed 14 Jul 2027	Wed 08:00	Wed 20:30
Wed 13 Jan 2027	Wed 19:30	Thu 09:00
Tue 13 Jul 2027	Tue 20:30	Wed 09:00

Note that an evening meeting in San Francisco is the next calendar day in Bangalore. Invites that cross midnight need the date checked on both sides.

Sydney and London

Usual gap: 9 to 11 hours, depending on the time of year (see below). Sydney and London both observe daylight saving, but in opposite seasons.

Date	London	Sydney
Wed 13 Jan 2027	Wed 08:00	Wed 19:00
Wed 13 Jan 2027	Wed 21:00	Thu 08:00
Wed 14 Jul 2027	Wed 08:00	Wed 17:00

In the northern summer, London’s early morning meets Sydney’s late afternoon. In the northern winter, the more workable option is usually London’s evening and Sydney’s next morning.

Step 2: check the daylight saving mismatch weeks

The US, Europe and Australia all change their clocks, but on different dates. In the gaps between their switches, the usual offsets are wrong.

United States and Europe. The US switches on the second Sunday of March and the first Sunday of November; the EU and UK switch on the last Sundays of March and October. In 2027:

Period (2027)	New York	London	Gap
Until 13 March	UTC−5	UTC+0	5 h
14 March – 27 March	UTC−4	UTC+0	4 h
28 March – 30 October	UTC−4	UTC+1	5 h
31 October – 6 November	UTC−4	UTC+0	4 h
From 7 November	UTC−5	UTC+0	5 h

So there are two weeks in spring and one week in autumn when a recurring “9:00 New York / 14:00 London” meeting lands at 13:00 in London. The same is true in 2026: London returns to GMT on 25 October and New York on 1 November, so the week of 26 October 2026 has a 4-hour gap. The same mismatch applies to every pair of US and European cities, for example Chicago–Berlin.

Northern and southern hemispheres. Sydney moves its clocks forward in October and back in April — roughly the opposite of London. In 2027 the gap changes four times:

Period (2027)	Sydney	London	Gap
Until 27 March	UTC+11	UTC+0	11 h
28 March – 3 April	UTC+11	UTC+1	10 h
4 April – 2 October	UTC+10	UTC+1	9 h
3 October – 30 October	UTC+11	UTC+1	10 h
From 31 October	UTC+11	UTC+0	11 h

Dates are the local dates of each switch; the changes themselves happen in the early hours. A recurring London–Sydney meeting therefore moves by an hour on one side four times a year.

Places without daylight saving — India, Singapore, Japan, China, most of Africa and South America — keep a fixed offset, so the gap to them changes only when the other city switches.

The world clock shows each city’s current offset. For anything recurring, check the dates around March, April, October and November specifically.

Step 3: write the invite unambiguously

A meeting time needs a zone, and the zone needs to be unambiguous.

• Use the IANA zone or a city name, not an abbreviation. “15:00 America/New_York” or “15:00 New York time” is clear in every season. “15:00 EST” is often written in summer, when New York is actually on EDT, and abbreviations such as CST and IST mean different things in different countries (see time zone abbreviations).
• Add the UTC equivalent. “15:00 New York (19:00 UTC)” lets anyone convert it with no knowledge of US daylight saving rules. For a single event, UTC is a fixed reference; for a recurring one, state which city the meeting is anchored to.
• Decide which city the series follows. Calendar apps store a recurring meeting in the organiser’s zone. If the organiser is in New York, the meeting stays at 09:00 New York time and moves for London during the mismatch weeks. That is usually correct — just say so in the invite.
• Write the date for both sides when it differs. “Tuesday 20:30 San Francisco / Wednesday 09:00 Bangalore”.
• Prefer 24-hour time or always include am/pm. “8:30” is an easy misreading in a cross-continent invite.

Step 4: share the inconvenient slots

When there is no overlap, as with San Francisco and Bangalore, someone joins early or late. For a recurring meeting, alternating the inconvenient slot — one week suits one side, the next week the other — spreads the cost. For a large distributed group, a common pattern is two sessions of the same meeting at different times, with notes shared between them.

Half-hour and 45-minute zones

Not every offset is a whole number of hours. India is UTC+5:30 throughout the country. Kathmandu is UTC+5:45. Parts of Australia, including Adelaide and Darwin, use half-hour offsets, and Newfoundland in Canada is UTC−3:30 in winter.

These offsets catch out mental arithmetic more than software. A meeting at the top of the hour in London lands at :30 in India and at :45 in Nepal, so if a team spans these places, it can be worth choosing a start time that is round for the majority and checking it for the rest with the converter.