I really struggled getting punctuation and brackets right to make this work, but see if this is any use to you.
EDIT 2: ATTACHMENT (version 1) REMOVED AS IT HAS AN ERROR (positioning of X axis tic marks) - PLEASE SEE A MORE RECENT POSTING FOR VERSION 3
EDIT 1: This attachment (version 1) only works if you use a full stop for separating the integer and decimal parts of your real numbers. If you use a comma for such separator please use the attachment version 2
in my later posting in this same thread.
It is a standard Cumulus template file so it needs to be 'processed' by Cumulus.
I have modified it with loads of extra script code. Best practice is to put such script in external files, but that requires some value passing between the file that Cumulus processes and the external script, and so for simplicity I have left all code in one file.
To make it work, you will need to add a few 'libraries' to whatever folder your HTML is uploaded to by Cumulus, or modify the appropriate 'src' attributes to tell the HTML where these libraries are to be found.
The first library is 'jQuery', that basically provides a shorthand for many common operations so that the person writing the code does not need to worry which browser version is being used, the jQuery will try all possible coding that a browser might respond to, silently failing on un-understood code. You can download the jQuery library each time it is needed, or download it once and store it on your server - see
http://jquery.com/download/ for details of the various approaches. Most versions of Microsoft's Internet Explorer work differently to other browsers, so my code looks for
jquery-1.9.1.js
if obsolete IE is being used, but for
jquery-2.1.1.js
by default.
The next library is 'HighCharts', my code looks for
highcharts.js
see
http://www.highcharts.com/download for a download that contains all the components, but again it can be grabbed as explained at that url.
I have also included an attempt to load
highcharts-exporting.js
that adds a symbol looking like three horizontal lines to the top right of the plot and from clicking that you can choose to print the graph, or convert the graph to a static picture as you requested.
Hopefully once you have assembled all that, it will run straight away with your own data, it picks up units from Cumulus, and auto-scales the plots. I have set it up so that it shows day boundaries that move across depending on the hour at the time when Cumulus processed the page. Cumulus needs to have been running for at least 12 hours to have all the 'recent tags' populated to give observations for the correct times.
I am not any sort of computer professional, attempting to do this was rather trial and error, but I learnt a few things that have helped me to improve the limited use I had of such charts previously. As I said before, I have steered clear of the complexity of the Mark Crossley example that Steve Loft directed you to, mine is a rough and ready demonstration of what can be achieved. All that I have done could probably be done better. I leave it to you to decide whether my attempt helps you to get whatever you want. I have added 3 buttons within the table: 'Cumulus' effectively reverts the web page back to its standard appearance by hiding the highchart image; 'Highchart' hides the standard cumulus large graph and the instruction about clicking the small charts; 'Both' restores the default when the page is first loaded of both being shown.
In terms of your original request, the recent tags only cover up to one week, so you could edit the arrays in my example for different resolutions (every 2 hours, every half-hour) and shorter overall periods (although I have designed mine to be zoomed in for shorter x periods) but not for periods greater than 7 days.
My own monthly example simply (for one chosen month) plots the highest and lowest values (of a selected criterion) in that month for each of the years I have on my dayfile.txt. So my code picks part of dayfile.txt, identifies the required field in each row, calculates the highest and lowest, and puts that into an array that the series uses. But of course it is a lot more complicated than that suggests.
Therefore I would suggest you set up 'XAMPP' on your pc so you have your own server with PHP and a database and you then have the flexibility that Mark employs to run queries and produce whatever you want. If you read some of his postings on the forum, he explains much of this.