Which time zone do I use as the reference for scheduling?

Reference the boss's or the stakeholder's zone first. They feel the least flexibility, so build the calendar around their working hours, then check the others against it. Everyone else's early and late limits become your fence.

Why should I list each person's working window before proposing times?

Because people say 'no' to proposals but reveal limits happily. Ask for each attendee's start and end local time only. When you line those windows up, the overlap is the meeting slot — you skip ten rounds of guessing.

How do I find the best slot when some people are sleeping?

Convert everyone's window to one zone and take the intersection. If nothing overlaps above 30 minutes, widen one person's window, or rotate meetings week to week so a different region eats the early slot each time.

Find the Perfect Meeting Slot Across 3 Time Zones

Every time you book a cross-time-zone call, someone loses. The West Coast person drags in at 7am, or the Sydney teammate sits through dinner with the mic on. The fix is not a bigger spreadsheet — it is narrowing down to one question: what blocks are compatible?

Here is the coordinator's method, the one that turns eight people and six zones into a single start time nobody groans at.

Step 1: Pick the anchored time zone

The stakeholder feels the least flexibility. If your boss refuses mornings, or the client only responds after noon, that zone becomes your anchor. Everyone else works around it. Build the window grid in the anchor's time, then translate.

Step 2: Collect windows, not preferences

People vote no to proposals but happily reveal a limit. Ask each attendee only: what are your local start and end times? For a New York, London and Sydney crew, that might look like:

Attendee	Local window
New York	09:00 – 18:00 (EST)
London	09:00 – 17:30 (GMT)
Sydney	09:00 – 17:00 (AEST)

Step 3: Convert and intersect

Translate everyone into one zone. In EST, London is 5 hours ahead and Sydney is 16 hours ahead (it differs by one in each season — DST moves these numbers). Compacted to EST:

New York: 09:00 – 18:00
London: 04:00 – 12:30
Sydney: 23:00 (prev) – 07:00

The overlap of the three is a thin band roughly 09:00–12:30 New York time. That is your window. In practice a 10:00 EST start lands at 15:00 in London and 02:00 the next day in Sydney — which tells you rotation is still worth discussing.

Step 4: Trade the morning fairly

When no window clears 30 minutes, rotate the sacrifice. Many teams grow the span by making one region take the early slot, alternating every week. A Tuesday slot alternated between Asia-light and Americas-light weeks spreads the pain so the same person is not always up first.

You can verify any proposed slot directly on the HourSwift converter by adding every attendee's zone and comparing the highlighted row on the 24-hour table. See also the golden-hour trick for US + Europe + Asia.