The short answer

São Tomé is 9 hours behind Japan Standard Time.

São Tomé
8:56:23pm
GMT · UTC+00:00 · Sat, Jun 27
Japan Standard Time
5:56:23am
JST · UTC+09:00 · Sun, Jun 28
Read across to convert
São Tomé
GMT · UTC+00:00
8:56pm ☾
Japan Standard Time
JST · UTC+09:00
5:56am ☾
Click any row to pin that hour across both zones.
12amSat
9am
WORK
1am
10am
WORK
2am
11am
WORK
3am
12pm
WORK
4am
1pm
WORK
5am
2pm
WORK
6am
3pm
WORK
7am
4pm
WORK
8am
5pm
9am
WORK
6pm
10am
WORK
7pm
11am
WORK
8pm
12pm
WORK
9pm
1pm
WORK
10pm
2pm
WORK
11pm
3pm
WORK
12amSun ·+1d
4pm
WORK
1amSun ·+1d
5pm
2amSun ·+1d
6pm
3amSun ·+1d
7pm
4amSun ·+1d
NOW
8pm
5amSun ·+1d
9pm
6amSun ·+1d
10pm
7amSun ·+1d
11pm
8amSun ·+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
7am–10am
=
Japan Standard Time
4pm–7pm
Popular conversions

Quick reference.

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

What each side covers.

São Tomé
GMT · UTC+00:00
8:56pm

São Tomé and Príncipe

Japan Standard Time
JST · UTC+09:00
5:56am
Cities on this clock

Frequently asked

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

What is the time difference between São Tomé and Japan Standard Time?
São Tomé 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 9am in São Tomé, what time is it in Japan Standard Time?
9am in São Tomé is 6pm in Japan Standard Time. Use the hour-by-hour table above to read any other time across — find the row and read the matching cell in the other column.
What's the best time for a call between São Tomé and Japan Standard Time?
There's no comfortable 9-to-5 overlap between São Tomé 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.