Working from Osaka for a San Francisco company: time zones, async and evenings
6 min read
Updated September 30, 2026
Since November 2021 I’ve worked fully remote from Osaka for Vercel, which is headquartered in San Francisco. Since 2024 I’ve led customer success for Asia Pacific and Japan, so a normal day has Japanese customers, colleagues around Asia Pacific, and people in California whose afternoon is my early morning.
The conclusion first, for skimmers: the useful overlap with San Francisco is about two hours of my morning, four days a week. Everything else has to work in writing, for someone who will read it while I’m asleep.
The time-zone math
Japan is on UTC+9 all year; it doesn’t use daylight saving time. San Francisco is on Pacific Time: UTC-8 in winter (PST) and UTC-7 in summer (PDT). So Japan is 17 hours ahead in winter and 16 hours ahead in summer. The US changes its clocks on the second Sunday of March and the first Sunday of November. Japan doesn’t move.
A shortcut that works: to go from Osaka time to San Francisco time, add 8 hours and go back one day (add 7 in winter). 9:00 on a Tuesday in Osaka is 17:00 on Monday in San Francisco in summer, and 16:00 on Monday in winter.
| Osaka (JST) | San Francisco, March to November (PDT) | San Francisco, November to March (PST) |
|---|---|---|
| Tue 7:00 | Mon 15:00 | Mon 14:00 |
| Tue 9:00 | Mon 17:00 | Mon 16:00 |
| Tue 10:00 | Mon 18:00 | Mon 17:00 |
| Tue 18:00 | Tue 2:00 | Tue 1:00 |
| Tue 23:00 | Tue 7:00 | Tue 6:00 |
| Wed 1:00 | Tue 9:00 | Tue 8:00 |
So the windows are:
- Osaka early morning, San Francisco afternoon. Roughly 7:00 to 10:00 in Osaka. Almost every call with HQ goes here.
- Osaka late night, San Francisco morning. From about 1:00 in Osaka. Only for things that can’t wait, like a launch or an incident.
- The Osaka evening is the middle of the night in California. Nobody at HQ needs you then, which is worth remembering.
Two things the table doesn’t show. First, the week is shifted. Monday morning in Osaka is Sunday afternoon in San Francisco, and their Friday afternoon is my Saturday morning. There are really four overlap mornings a week, Tuesday to Friday, not five.
Second, recurring meetings set on a San Francisco calendar move for you twice a year. A 15:00 Pacific meeting is at 8:00 in Osaka in winter and at 7:00 from March. The calendar does the conversion; it doesn’t ask whether 7:00 still works for you. Check your week every time the US changes its clocks.
Asia Pacific is the easy part. Seoul is on the same time as Japan, Singapore is an hour behind, and Sydney is one or two hours ahead depending on its own daylight saving, which runs the other way (October to April). India is three and a half hours behind. If a regional meeting has to work from India to Sydney, early afternoon in Japan is the slot: 13:00 in Osaka is 9:30 in India, 12:00 in Singapore and 14:00 or 15:00 in Sydney.
What goes async and what deserves a call
With a couple of hours of overlap, a call is expensive, so it should be for something a document can’t do. My rule of thumb:
Async by default:
- Status updates and forecasts.
- Questions with one right answer.
- Reviews of a document, a proposal or a deck.
- Approvals, as long as the request carries enough context to say yes in one reply.
Worth a call:
- A disagreement. If a thread has gone back and forth three times, the fourth message should be a meeting invite.
- Feedback for a person, especially the hard kind.
- The first conversation with someone new. After one call, their messages get much easier to read.
- Customer moments: an executive business review, or a customer who is upset.
Even then, write first. A call about a draft is short; a call to produce the draft is long, and someone still has to write it up afterwards.
Now, don’t get me wrong. Working sixteen hours away has real costs. You miss the hallway context, and decisions made in a San Francisco meeting reach you as a summary, if they reach you at all. Good writing reduces that; it doesn’t make it go away.
Writing habits that make async work
When my day ends it’s the middle of the night in San Francisco, and when theirs ends I’m halfway through my morning. Whatever I leave behind gets read while I’m asleep, so it has to stand on its own.
Handoffs
A handoff should let the other person act without asking anything. The format I’d suggest:
Handoff: [customer or project], Tue 18:00 JST / Tue 02:00 PDT
Status: where things are, in two lines
Decided: what's settled, so nobody reopens it
Need from you: who, what, by when (in your time zone)
If I don't hear back: what I'll do, and when
Links: the thread, the doc, the ticket
The last two lines do the most work. “If I don’t hear back, I’ll send the Japanese version to the customer on Thursday morning” turns a question that could cost a day into a default that only needs a reply if someone disagrees.
Decision docs
For anything bigger, write a short decision doc: the context, the options, your recommendation, who decides and by when. The recommendation is the part people leave out, and across time zones it matters most. Someone sixteen hours away can approve a recommendation in one reply. A list of options with no recommendation costs a full day per round trip.
Small habits
- Put the ask in the first line.
- Write a time zone next to every time: “Thursday 10:00 JST (Wednesday 18:00 PDT).”
- Avoid “tomorrow” and “end of day.” On a Monday afternoon in San Francisco, “tomorrow” means Tuesday; for me it’s already Tuesday, so tomorrow sounds like Wednesday.
- Link to the source instead of paraphrasing it. The document will be updated; your summary won’t.
Protecting evenings
The math makes it tempting to be always on. San Francisco comes online around 1:00 or 2:00 in Osaka, so someone is always awake, and if you answer at midnight, people learn that you answer at midnight.
Some of my evenings also have a fixed commitment. Since July 2024 I’ve done live English interpretation of M.League, Japan’s professional mahjong league, with pro Kei Nakabayashi on his YouTube channel: he commentates in Japanese and I interpret into English as he talks. M.League is played in the evening, Japan time, and you can’t check Slack while interpreting a live broadcast. Those nights have to be blocked on the calendar like any customer meeting.
What I’d suggest to anyone in the same position:
- Put your working hours in your calendar and your chat profile, in both time zones.
- Block the evenings you need, with a reason people can see. “Broadcast” is enough.
- Agree with your manager on what is worth a late call: a production incident for a customer, a launch. Everything else waits for the morning window.
- If you do take a late call, take the time back the next day.
The Japanese part of the day belongs to Japanese customers and to Asia Pacific anyway. Spending it on calls with HQ that could have been a document is how you end up working a Japanese day and an American one.
The setup, briefly
Nothing special. A MacBook Pro with an M1 Max, two monitors on a KVM switch, a Logicool webcam that has survived years of customer calls, team meetings and broadcasts, and a Mac mini that runs my own Claude-based assistant. The full list is on the Uses page. If most of your overlap is video calls, spend on the camera and a stable connection before anything else.
The other half of this job, explaining Japanese customers to headquarters, is in Explaining Japanese enterprise deals to a US headquarters.
Put a time zone next to the next deadline you write.