How to track time at overseas supplier offices

When a supplier is several time zones away, a quick message can arrive outside office hours, or a meeting can land on the wrong day. The difference may also change when one country switches to daylight saving time and the other does not.

Use the World Clock to keep your time and the supplier's local time in view together. These steps will help you choose the right location, read the date correctly, and avoid relying on a time difference that may change during the year.

Set up a clock for the supplier's office

1. Open the World Clock and add your own city and the city where the supplier's office is located. Use the actual office location, not just the supplier's country.
2. Check that both locations appear with their local times and dates. If the supplier has offices in several cities, include each location you contact regularly.
3. Compare the clocks during your normal workday. Note a few hours when both offices are likely to be open, and avoid assuming that the same time difference applies all year.
4. Keep the World Clock available when planning calls or following up on a delivery. Before sending an invitation, check the supplier's local date as well as the hour.

For example, Chicago is usually six hours behind UTC in winter and five hours behind in summer. Tokyo stays at UTC+9 year-round. When it is 4 p.m. in Chicago, it is 7 a.m. the next day in Tokyo during Chicago's standard time, and 6 a.m. the next day during daylight saving time. A clock that shows both cities helps you see the date change as well as the hour.

What the time comparison means

The supplier's clock shows the next calendar day

This is normal when the offices are far apart. A morning in one location may fall on the previous evening or the following morning in another. Write the date and time together when confirming a deadline, such as Tuesday, June 9 at 10 a.m. in Tokyo, rather than saying only "tomorrow morning."

The gap changes during the year

One location may observe daylight saving time while the other does not, or their clock changes may happen on different dates. The gap can therefore shift by an hour for part of the year. Check the displayed local times again when the seasons change, especially before recurring meetings.

The supplier's country has more than one time zone

A country name is not always enough to identify local time. Large countries can have several time zones, and some regions use different rules from nearby regions. Match the city where the staff or warehouse is located, and ask the supplier to confirm if the office location is unclear.

The time looks right, but the office is closed

Local time alone does not tell you whether the supplier is working. Business hours, lunch breaks, weekends, public holidays, and temporary closures all matter. Confirm the office's usual hours and check for local holidays before treating a delayed reply as a problem. See what to check when a supplier's local holiday starts.

Keep supplier times accurate

1. Use a city, not a fixed offset. A fixed value such as UTC+8 does not account for seasonal clock changes. Choose the supplier's city when possible, so the displayed time follows that location's time-zone rules.
2. Confirm which office you mean. Ask for the city or region of the person handling your order. A sales contact and a warehouse may be in different places, even when they work for the same supplier.
3. Check the date before sending a deadline. If the clock shows the next day at the supplier's location, state that date explicitly in your message or meeting invitation. This prevents confusion about whether a deadline is due today or tomorrow.
4. Recheck after a seasonal clock change. Daylight saving dates vary by location. Compare the clocks again when either office changes its clocks, rather than keeping an old conversion in a note or spreadsheet.
5. Confirm working hours and holidays. Ask the supplier what hours their team normally works and which local holidays affect the office. A correct clock cannot show a company-specific closure.

Plan a meeting both offices can attend

Start with the hours when your own team is available, then look for an overlap with the supplier's working day. For instance, if your afternoon corresponds to very early morning at the supplier's office, try moving the call earlier or later on your side. If the overlap is only a narrow window, agree on it directly instead of assuming a calendar invitation will be convenient.

For recurring meetings, include the time zone or city in the invitation and review the series after seasonal clock changes. A meeting set for 9 a.m. in one city may still stay at 9 a.m. there while shifting by an hour for attendees elsewhere. Check the displayed local time before each important call, particularly after travel or a change to the supplier's office location.

When a date or deadline matters, confirm it in writing using the supplier's city, local date, and time.