Scheduling meetings across US time zones
For the four mainland zones on a 9-to-5 day, the only hours everyone shares are 12:00 to 5:00 PM Eastern (9:00 AM to 2:00 PM Pacific). Add Alaska and the window shrinks to four hours; add Hawaii and it shrinks to two or three, depending on the season. The table below is computed for a summer day and a winter day with the same math as themeeting planner.
Shared working hours by zone combination
Working hours are 9:00 AM to 5:00 PM local time in every city. Times are shown in the first city’s zone.
| Zones | July 15, 2026 | January 15, 2026 | Plan |
|---|---|---|---|
| Eastern + Central | 10:00 AM–5:00 PM EDT (7 h) | 10:00 AM–5:00 PM EST (7 h) | Open plan |
| Eastern + Pacific | 12:00 PM–5:00 PM EDT (5 h) | 12:00 PM–5:00 PM EST (5 h) | Open plan |
| Eastern + Arizona | 12:00 PM–5:00 PM EDT (5 h) | 11:00 AM–5:00 PM EST (6 h) | Open plan |
| All four mainland zones | 12:00 PM–5:00 PM EDT (5 h) | 12:00 PM–5:00 PM EST (5 h) | Open plan |
| Mainland + Alaska | 1:00 PM–5:00 PM EDT (4 h) | 1:00 PM–5:00 PM EST (4 h) | Open plan |
| Mainland + Hawaii | 3:00 PM–5:00 PM EDT (2 h) | 2:00 PM–5:00 PM EST (3 h) | Open plan |
| Pacific + Hawaii | 12:00 PM–5:00 PM PDT (5 h) | 11:00 AM–5:00 PM PST (6 h) | Open plan |
Why the windows change with the season
Most US zones move their clocks together on the second Sunday in March and the first Sunday in November, so the gap between New York, Chicago, Denver and Los Angeles stays the same all year. Two places don’t move: most of Arizona stays on Mountain Standard Time and Hawaii stays on Hawaii Standard Time. Every pairing with them shifts by an hour twice a year.
That’s why the table shows Phoenix sharing different hours with New York in July and January. In summer, Phoenix matches Los Angeles; in winter, it matches Denver. Hawaii is six hours behind New York in summer and five in winter, so East Coast and Hawaii teams gain one shared hour from November to March.
Practical rules for coast-to-coast meetings
- Anchor on the westernmost city. Its 9:00 AM is the earliest start that works for everyone; for Pacific teams that is noon Eastern.
- Write the zone as “ET”, “CT”, “MT” or “PT”. “EST” in July is technically an hour off; see EST vs EDT.
- Check dates near a DST switch. A recurring Phoenix or Honolulu meeting moves by an hour for one side after each change.
- Rotate when there is no overlap. When a team spans Hawaii and the East Coast with long days, alternate early and late slots instead of always making one side stay late.
- Send a calendar invite, not a time in text. Calendar apps convert from the IANA zone automatically; a typed time doesn’t.
Worked example
A team in Boston, Denver and Seattle wants a weekly 45-minute call. Seattle (Pacific) is three hours behind Boston and Denver is two. Seattle’s 9:00 AM is noon in Boston and 10:00 AM in Denver; Boston’s 5:00 PM is 2:00 PM in Seattle. So any start between 12:00 and 4:15 PM Eastern works for all three, and a 1:00 PM Eastern slot leaves an hour of margin on both ends. None of these cities skips DST, so the slot holds all year.
Key takeaways
- Mainland US teams share at most five working hours a day: 12–5 PM Eastern.
- Arizona and Hawaii change their gap to everyone else twice a year.
- Use the meeting planner for your exact cities and date, and the converter for a single time.
Sources
- Overlap windows: computed from the IANA time zone database in the build environment (same code as the meeting planner).
- US daylight saving dates: 15 U.S.C. § 260a, as amended by the Energy Policy Act of 2005.