The short answer

8am in São Tomé and Príncipe is 5pm in Japan Standard Time.

São Tomé and Príncipe is 9 hours behind Japan Standard Time. That's already evening in Japan Standard Time, after the typical working day ends.

São Tomé and Príncipe
8am
Japan Standard Time
5pm
Right now
5:57amGMT · UTC+00:00 · Wed, Jun 24
2:57pmJST · UTC+09:00 · Wed, Jun 24
Read across to convert
São Tomé and Príncipe
GMT · UTC+00:00
5:57am ☾
Japan Standard Time
JST · UTC+09:00
2:57pm ☀
Pinned8amSão Tomé and Príncipe=5pmJapan Standard Time
12amWed
9am
WORK
1am
10am
WORK
2am
11am
WORK
3am
12pm
WORK
4am
1pm
WORK
NOW
5am
2pm
WORK
6am
3pm
WORK
7am
4pm
WORK
PINNED
8am
5pm
9am
WORK
6pm
10am
WORK
7pm
11am
WORK
8pm
12pm
WORK
9pm
1pm
WORK
10pm
2pm
WORK
11pm
3pm
WORK
12amThu ·+1d
4pm
WORK
1amThu ·+1d
5pm
2amThu ·+1d
6pm
3amThu ·+1d
7pm
4amThu ·+1d
8pm
5amThu ·+1d
9pm
6amThu ·+1d
10pm
7amThu ·+1d
11pm
8amThu ·+1d
daylightnightworking hoursoverlap
Best time to meet
Closest workable window
Just outside the working window — early on one side, late on the other.
São Tomé and Príncipe
7am–10am
=
Japan Standard Time
4pm–7pm
Popular conversions

Quick reference.

9amSão Tomé and Príncipe=6pmJapan Standard Time
12pmSão Tomé and Príncipe=9pmJapan Standard Time
3pmSão Tomé and Príncipe=12amJapan Standard Time · next day
5pmSão Tomé and Príncipe=2amJapan Standard Time · next day
9pmSão Tomé and Príncipe=6amJapan Standard Time · next day
In context

What each side covers.

São Tomé and Príncipe
GMT · UTC+00:00
5:57am
Cities on this clock
Japan Standard Time
JST · UTC+09:00
2:57pm
Cities on this clock

Frequently asked

Quick answers about converting between São Tomé and Príncipe and Japan Standard Time. Can't find what you need? Email [email protected].

What is the time difference between São Tomé and Príncipe and Japan Standard Time?
São Tomé and Príncipe is 9 hours behind Japan Standard Time right now. We always show the live, daylight-saving-correct difference, so this figure already accounts for whichever side is observing summer time today.
When it's 8am in São Tomé and Príncipe, what time is it in Japan Standard Time?
8am in São Tomé and Príncipe is 5pm in Japan Standard Time. That's already evening in Japan Standard Time, after the typical working day ends. Use the hour-by-hour table above to read any other time across.
What's the best time for a call between São Tomé and Príncipe and Japan Standard Time?
There's no comfortable 9-to-5 overlap between São Tomé and Príncipe and Japan Standard Time — they sit on opposite sides of the planet's working day. Plan for an early or late call on one side, or hand work off asynchronously.
Does this account for daylight saving time?
Yes. We track every clock change in both places, so the abbreviations you see — GMT and JST — are the ones actually in effect right now, not a fixed all-year value. When either side changes its clocks, this page updates automatically.
Why is the date sometimes different on each side?
When two places are far enough apart, the same moment can fall on different calendar days. That is why some conversions are marked "previous day" or "next day" — it is the same instant in time, read off two clocks that crossed midnight at different points.