About this tool
This converter turns a time in Los Angeles into the matching time in Tokyo, or the other way round, for any date you choose. It shows both cities' clocks live, the hour difference on the chosen date, a 24-hour conversion table with next-day markers, the small window where both cities are inside working hours, and the dates of California's clock changes for the year. Tokyo is 17 hours ahead of Los Angeles in the northern winter and 16 hours ahead in summer, because Japan does not observe daylight saving time while California does. Since the gap is close to a full day, almost every daytime hour in Los Angeles is already the next calendar date in Tokyo, and the page makes that day change explicit. It is built for people scheduling calls with Japan, following Japanese events from the US West Coast, or planning flights between LAX and Haneda or Narita.
How it works
Both cities are IANA time zones (America/Los_Angeles and Asia/Tokyo) and every offset comes from the browser's time zone database through Intl.DateTimeFormat, never from a hard-coded table, so the daylight-saving rules in force on the chosen date are applied automatically. To convert, the wall-clock time you enter is first treated as UTC, the source zone's offset at that guess is subtracted, and the check is repeated once so times on a clock-change day land on the correct side of the change. The resulting instant is then formatted in the other zone to give the local date and time; the day marker is the difference between the two calendar dates. The hour difference shown is the target offset minus the source offset at that instant, and the year table is built by sampling the two offsets at noon UTC on every day of the year and grouping the runs where the difference stays the same.
Frequently asked questions
Is Tokyo 16 or 17 hours ahead of Los Angeles?
17 hours while Los Angeles is on Pacific Standard Time (early November to early March) and 16 hours during Pacific Daylight Time (second Sunday in March to first Sunday in November). Japan does not observe daylight saving, so the change comes entirely from the California side. In 2026 the 16-hour period runs from March 8 to October 31.
Is it always the next day in Tokyo?
During Los Angeles daytime, yes. From 7:00 am Los Angeles time in winter (8:00 am in summer) onward, Tokyo has already passed midnight and is on the next calendar date, so a Monday morning meeting in Los Angeles is Tuesday morning in Tokyo. Only between midnight and about 7:00 am in Los Angeles do the two cities share a date.
Why is there almost no overlap in working hours?
Because the gap is 16 to 17 hours, Tokyo's 9-to-5 day falls between 4:00 pm and midnight the previous day in Los Angeles. In winter 4:00 pm Los Angeles is exactly 9:00 am Tokyo, giving a single hour of overlap; in summer 5:00 pm Los Angeles is 9:00 am Tokyo and there is none. Most teams settle on early evening in Los Angeles or early morning in Tokyo.
Does Japan have daylight saving time?
No. Japan used summer time from 1948 to 1951 under the Allied occupation and abolished it in 1952; Japan Standard Time has been UTC+9 all year since. Proposals to bring it back, including for the Tokyo 2020 Olympics, were rejected. That is why the hour difference from Los Angeles changes only when California's clocks change.