The rule is written down and it is not complicated: on the hourly chart, buy when a candle closes above the previous day’s high. On Thursday you take the trade at 11.15 and it works out reasonably. On Friday your friend says he never got the signal — he watched the same stock all day on the same rule and his chart never printed an hourly close above the level. You compare screens over the weekend. His candles are labelled 10.00, 11.00, 12.00. Yours are labelled 10.15, 11.15, 12.15. Every candle on the two charts covers a different stretch of the day, so every open, high, low and close on them is a different number, and one written rule has quietly become two.
An earlier lesson in this track listed candle anchoring among the reasons two apps show you different charts. This lesson is the arithmetic underneath it, because it is not a quirk of one platform. The Indian equity [[Trading session]] has a length that most of the common bar sizes do not divide into, and once that is true, every platform has to make a choice, and there is no choice that is obviously right.
A carpenter has a plank seven and a half feet long and is asked for shelves a foot wide. He can cut seven full shelves and leave a half-foot offcut at one end, or start half a foot in and leave the offcut at the other, or split the remainder between both ends. Every one of those is a competent job. Ask two carpenters and you get two sets of shelves from the same plank, and only the length of the plank was ever fixed.
The session is the plank. The bar size is the shelf. The exchange fixed the plank at 375 minutes and fixed nothing else, so where the cuts fall is the platform’s decision — and the offcut, the short bar at one end, is a real candle that your rules will read as though it were a full one.
The number the whole lesson turns on
The equity session runs from 9.15 in the morning to 3.30 in the afternoon. That is 375 minutes, and 375 is three times five times five times five. Which means the bar sizes anybody actually charts on that cut it into equal pieces with nothing left over are exactly these, and no others. (125 and 375 divide it too, and nobody draws a chart with three candles on it.)
| Bar size | Bars in a session | Does it divide the session? |
|---|---|---|
| 1 minute | 375 | Yes |
| 3 minutes | 125 | Yes |
| 5 minutes | 75 | Yes |
| 15 minutes | 25 | Yes |
| 25 minutes | 15 | Yes, and almost nobody uses it |
| 75 minutes | 5 | Yes, and almost nobody uses it |
| 10 minutes | 37.5 | No — a five-minute stub at one end |
| 30 minutes | 12.5 | No — a fifteen-minute stub at one end |
| 60 minutes | 6.25 | No — a fifteen-minute stub at one end |
| 2 hours | 3.125 | No — three full bars and a fifteen-minute stub, as with thirty and sixty |
Two honest ways to cut an hour
[[Candle anchoring]] is the convention that decides where a platform starts counting. There are two in common use, both defensible, and the difference between them is fifteen minutes applied to every boundary in the day.
- 9.15 – 10.15, a full sixty minutes
- 10.15 – 11.15, 11.15 – 12.15, 12.15 – 13.15
- 13.15 – 14.15, 14.15 – 15.15
- And then 15.15 – 15.30: a fifteen-minute stub at the close
- Seven candles. The first six are hours; the last is a quarter of one
- 9.15 – 10.00, a forty-five-minute stub at the open
- 10.00 – 11.00, 11.00 – 12.00, 12.00 – 13.00
- 13.00 – 14.00, 14.00 – 15.00
- And then 15.00 – 15.30: a thirty-minute stub at the close
- Seven candles again, with a stub at both ends instead of one
What that does to a rule that names a bar
The same series drawn at different resolutions. What the lab cannot show you, and what this lesson is about, is that at some resolutions the last bar of the day is not the same length as the others.
Where the stub bar quietly matters
- The last signal of the day comes off a short bar. On a session-anchored hourly chart the closing candle is fifteen minutes long. It has a smaller range and less volume than every other candle on the screen, purely because it had a quarter of the time — so a close-based crossover, a breakout confirmation or a doji reading taken from it is being taken from a bar built differently from the ones the rule was tested on.
- The [[Opening range]] is defined by the anchor, not by the market. “The first hour’s high” is the high to 10.15 on one chart and to 10.00 on the other. Imported material that says the first hour was written for a session with a different length, and translating it to India means choosing one of these and saying which.
- Bar-count lookbacks change meaning. A twenty-bar Donchian channel on a thirty-minute chart is 600 minutes of trading, which is one and three-fifths of a session — so on a chart with a stub bar the window straddles session boundaries at a slightly different point every day.
- Screener results depend on it. A scan for “stocks whose hourly candle closed above the twenty-hour average” run on two data vendors will return two overlapping but different lists, every day, with no error anywhere.
- Alerts fire at different times. Which matters most to the person who cannot watch the screen and has set the alert precisely because of that.
What to do about it, once
- 1Read the timestamps on your own hourly chart
Not the shape — the labels. Bars starting 9.15, 10.15, 11.15 are session-anchored. A short first bar to 10.00 followed by clean clock hours is clock-anchored. This takes ten seconds and most people have never done it.
- 2Prefer a bar size that divides the session
Five, fifteen and twenty-five minutes cut 375 exactly, and so does seventy-five. On those, the anchoring question does not arise at all, because there is only one way to cut the plank. If your method genuinely needs hours, that is fine — it just means the anchor is now part of the method.
- 3Write the anchor into the rule, in the same line as the bar size
“Hourly, anchored to the session open” is a rule. “Hourly” is a preference. The distinction only shows up when somebody else — or a backtest, or a new platform — has to reproduce what you did.
- 4Decide what the stub bar is allowed to do
Either exclude the short closing candle from close-based signals, or include it deliberately and know that it is a quarter-length observation. Both are defensible. Silently including it is what produces the end-of-day signal nobody can explain the next morning.
- 5Check the anchor again after you change platform
It is not a setting most people migrate, because most people do not know it exists. A strategy that stops working the month you switched apps is worth testing against this before it is retired.
Why do so many Indian intraday traders end up on the five-minute and fifteen-minute charts rather than on ten-minute or hourly ones?
Darzi ke paas 375 centimetre ka thaan hai aur aapko 60-60 centimetre ke parde chahiye. Chhe parde ban jaate hain, yaani 360, aur 15 centimetre bach jaata hai. Ab woh 15 shuru mein chhode ya aakhir mein — dono kaam theek hain, aur do darzi do alag set banayenge. Session bhi wahi 375 minute ka thaan hai, 9.15 se 3.30. Isiliye 5, 15, 25 aur 75 minute ke chart poore-poore kat jaate hain (15 waale mein theek 25 candle, ghanti se ghanti tak), aur ghante waale mein nahi kat te. Ek app bacha hua 15 minute aakhir mein rakhta hai — candle 9.15, 10.15, 11.15 — doosra shuruaat mein, yaani pehli candle 9.15 se 10.00 ki chhoti si, phir 10.00, 11.00. Dono chart pe saat candle hain aur sirf do kinare same hain: 9.15 aur 3.30; beech ki ek bhi candle common nahi. Isiliye aapka rule 11.15 pe laga aur dost ka poore din nahi laga. Rule mein bar ki lambai likhi thi, anchor likha hi nahi tha.
- The equity session is 375 minutes, and only 1, 3, 5, 15, 25 and 75-minute bars divide it exactly.
- Any other bar size leaves a stub candle, and the platform decides which end of the day it sits at.
- Two hourly charts of the same session — one anchored to 9.15, one to the clock — share only their first and last boundary.
- A timeframe is two decisions: the length of the bar and the anchor. A rule that states only the first is not reproducible.
- The closing candle on a session-anchored hourly chart is a quarter-length bar that every close-based rule reads as a full one.
Mark it done to track your progress through the curriculum.