Time, which is where nearly everyone gets it wrong
Your broker's clock decides nothing
Your broker may be on GMT+2, GMT+3 or wherever suits it. That does not change when London opens. London opens at eight in the morning London time, and the CPI figure comes out when whoever publishes it publishes it.
Tempo uses broker time only to draw, because it is the time your candles carry. Everything else — when each session opens, when each killzone runs, what time a release comes out — is worked out in the relevant market's own time.
The offset is measured, not typed in
Many tools ask you to type "my broker is GMT+3" into a box. That is a number that goes stale on its own: the clocks change, the broker moves from GMT+3 to GMT+2, and the panel lies for months without anything failing.
Tempo measures it, in two ways that complement each other:
- Right now, by comparing the server's clock with the real time on your computer.
- For every past week, by looking at the price history of your own symbol. The currency market opens on Sunday at 17:00 New York; the first candle of each week, stamped in server time, tells you what offset the broker had that week.
With the weeks measured, Tempo recognises your broker's rule — it changes its clock with the United States, with Europe, or not at all — and uses it for dates it could not measure.
Why "every week" matters
Because the session shading is drawn over candles from several days, and some of them are from before the last clock change. Using today's offset for all of them would shift the ones from before the change by an hour: "fine on Friday, wrong on Monday". Tempo shades every candle with the offset and the summer time of its own date.
You can read it
On the strip's second text row:
Server GMT+3 · US DST on · EU DST on
That is your broker's offset right now and whether each side of the Atlantic is on summer time. If you ever doubt whether the sessions are in the right place, that is the figure to check against.
The weeks when the two sides of the Atlantic disagree
Europe changes its clocks on the last Sunday of March and the last Sunday of October. The United States, on the second Sunday of March and the first Sunday of November.
They are not the same days. There are three or four weeks a year when the offset between London and New York is not the usual one: instead of five hours it is four.
In those weeks, tools that assume a fixed offset draw the bands an hour out. They do not raise an error — they draw it wrong, which is worse, because it leaves you thinking you are the one who got confused.
Tempo says so. When the London–New York offset is not the normal one, the strip warns you instead of keeping quiet, and the time model on the second row shows which side has already changed.
Tokyo does not change its clocks
Japan has no summer time. The Tokyo session is always in the same place in local time, and it moves relative to the other two when they change. That is not a drawing error: it is how the world is.
In the Strategy Tester
In the Strategy Tester MetaTrader returns the server's own time as the "real" time, so measuring the offset by comparing clocks would always give zero. Tempo does not trust that: in the Tester it uses only what it measured from the price history. If there is not enough history to measure it, the strip says so ("Server time offset unknown") and does not draw the sessions in a made-up place.
The economic calendar does not exist in the Tester either; the strip says that too.