Will you add a harmonic trading function?

Can you show me an example of a harmonic trading indicator?

You can download here.
http://www.fx-mt4.info/view-review/zup-v93-indicator-harmonic-price-pattern-recognition

AFAIS, this indicator just paints a quad or butterfly in a chart. What do you want to do with it in Zorro?

An automated harmonic trading.
You can find a more info about it.
http://www.fxgroundworks.com/

That looks like a website that sells scam products. I find also no info on that site how their filters are supposed to work - for implementing an indicator, I need to know what output signal this indicator should generate.

Do you think a harmonic works?
You said in the manual that fibonacci numbers don't work as it is linked to them.

I don't know if it works. But a price curve has normally an autocorrelation range of less than 4 or 5 bars. So there is no reason to assume that a butterfly or some other figure can give insight in the further price movement. And I have not heard that anyone has found so far any evidence that such methods work.

It will be useful if the Zorro chart shows times of the each bars.

Why Zorro says errors when I try to save a chart image?

For saving a chart image, just click on Image / Save As Picture.

The chart shows the time, but in a relatively low resolution. I'll check if the chart x axis can get a finer resolution.