Tukuk-OS🕒 Port Louis to Tokyo time
| Port Louis on 2026-11-06 | 12:00 (GMT+4) |
| Tokyo at that instant | 17:00 the same day (GMT+9) |
| Difference on this date | 5 hours (2026-01-01 to 2026-12-31) |
| 2026-01-01 to 2026-12-31 | 5 hours |
| Next clock change, Port Louis | none in the next 200 days |
| Next clock change, Tokyo | none in the next 200 days |
| 09:00 in Port Louis is | 14:00 in Tokyo |
| 12:00 in Port Louis is | 17:00 in Tokyo |
| 18:00 in Port Louis is | 23:00 in Tokyo |
| Shared 09:00–17:00 working window | 09:00–12:00 in Port Louis, 14:00–17:00 in Tokyo |
ℹ️ What this tool does & how it works
On 2026-11-06 the two clocks are apart by 5 hours, with Tokyo ahead. Port Louis runs on GMT+4 and Tokyo on GMT+9. Across 2026 the difference runs: 2026-01-01 → 2026-12-31: 5 hours. Pick any date and time below and the page reworks the whole table from your own device.
Why Port Louis and Tokyo keep a fixed gap all year
Nothing moves here. Port Louis keeps GMT+4 and Tokyo keeps GMT+9 the whole year round, because neither jurisdiction changes its clocks — the arrangement most of the world's population lives under, since daylight saving has been abandoned or never adopted across much of Asia, Africa and the Americas outside the United States and Canada, and near the equator there is little daylight to shift in the first place. So the two are 5 hours apart in January and in July alike, and choosing a date on this page changes the arithmetic, not the answer.
The clock changes, and who decides them
Port Louis uses the zone Indian/Mauritius, which does not change its clocks. Tokyo uses the zone Asia/Tokyo, which does not change its clocks. Neither figure is a physical fact: an offset is legislation, and the same fifteen degrees of longitude can sit under three zones because a border runs through it. That is why this page reads its offsets out of the time-zone database built into your own browser instead of hardcoding a table of abbreviations — it is the database your operating system already keeps current, and it is what puts Port Louis and Tokyo in the right relation even when a government moves a date at short notice. A device whose database predates the last change gets the old answer, which is the one caveat worth knowing.
What it is actually like to work across the two
Both places are inside their own 09:00–17:00 on 3 hours of the day: 09:00–12:00 in Port Louis, 14:00–17:00 in Tokyo — outside those hours somebody is starting early, finishing late or taking the call at midnight. The two clock rules here are not unique to these two places: 15 other cities in our dataset keep the same clock as one of them, including Dubai, Abu Dhabi, Muscat, Baku, Tbilisi, so looking any of those up against the city on the other side of the pair gives this page’s answers. The arithmetic is the three lines the page runs in front of you: read each zone’s offset for the date you picked, subtract, and let the modulo handle the dateline.