One of the main reasons to work with a nearshore team is shared working hours. But "similar time zone" is vague. This guide shows how to calculate the real overlap between a team in Mexico and your US location, how daylight saving time changes it, and how many shared hours different kinds of work need.
How to calculate overlap
Overlap depends on the difference in UTC offsets between the two locations. If both teams work 9:00 to 18:00 local time, the shared hours equal nine minus the number of hours between the two time zones. For example, a one-hour difference leaves eight shared hours, and a two-hour difference leaves seven. This ignores lunch and breaks, which reduce the usable overlap.
Mexico City against US time zones
Mexico City stays on UTC−6 all year, because most of Mexico ended daylight saving time in October 2022. The United States changes clocks, so the overlap shifts during the year. For a 9:00 to 18:00 workday on both sides:
- Pacific time: about 7 shared hours in winter and 8 in summer.
- Mountain time: about 8 shared hours in winter and 9 in summer.
- Central time: about 9 shared hours in winter and 8 in summer.
- Eastern time: about 8 shared hours in winter and 7 in summer.
"Winter" and "summer" here mean US standard time and US daylight saving time, which runs from the second Sunday of March to the first Sunday of November. These are approximate figures; before lunch and breaks, the range is roughly 7 to 9 hours. A few places differ: Sonora (UTC−7) and Quintana Roo (UTC−5) use fixed offsets, and Baja California and several northern border municipalities follow US daylight saving time.
How many shared hours do you need?
There is no universal number. As a practical rule of thumb, which is our guidance rather than a standard, think in terms of the kind of work:
- Discovery, planning, and ambiguous work benefit from many shared hours. Conversations, whiteboarding, and quick clarifications are faster in real time.
- Pairing, debugging, and incident response need overlap at the moment problems happen.
- Well-specified implementation can run with fewer shared hours if requirements and acceptance criteria are clear and reviews are prompt.
- Reviews and approvals need a predictable window when the people who decide are available.
With 7 to 9 shared hours in a 9:00 to 18:00 day, you can usually schedule these activities inside the shared window instead of working around it.
How to use the overlap well
- Define core hours. Agree a window every day when both sides are available for questions, reviews, and meetings.
- Put the live work there. Planning, demos, reviews, and decisions belong in the shared hours; focused work can happen outside them.
- Write things down. Short written updates and clear tickets keep work moving when someone is offline.
- Plan around clock changes. When US daylight saving time starts or ends, the overlap shifts by an hour. Check the calendar for those weeks.
- Respect local holidays on both sides when you plan deadlines.
Offshore comparison
Offshore teams many time zones apart can have little or no overlap, so work tends to run asynchronously, sometimes with a day of latency between question and answer. That suits some projects and slows down others, as we discuss in Nearshore vs. Offshore: Why Mexico.
See your own overlap
On the Nearshore AI Pods page there is a map showing the overlap by US time zone. If you want to test how a team works inside your hours, read how to run a 2-week trial.