Nanohah: Can I create a graph like in my picture example where the x axis has the date and I can just add in new numbers on those dates and it will save it? It does not need to be online.
Buster2000: It sounds complicated to deal with an API for this, I need to also make a webpage to use it?
What I am looking for is very basic in my eyes, just some chart where I can create items and then insert numbers for specific dates and it should show them up at those dates, and I can look at it over the week, month or year etc and also toggle individual items on or off to hide and show them in the graph.
You can create a graph like in the image you showed using OpenOffice Calc (free). You can do it so you can add more entries later but that will require either you to know in advanced how many more entries you will have or a little bit of effort each time you add new entries (it's very little effort but it's more than just typing in a few new numbers). I should add that toggling items on and off is not very trivial with OpenOffice though, I can't see how to do it at all short of making a new graph.
You are asking for quite a flexible and user friendly thing where you can just add data on the fly and have it rebuild itself and I am sure there is something like that out there. This does the job: https://nces.ed.gov/nceskids/createagraph/default.aspx? It mentions saving so you could maintain something on there if it's just a personal thing and modifying seems simple enough. It doesn't seem to let you hide series though.
A few years ago I made an app and needed quite a dynamic graph, I think I used this: http://www.android-graphview.org. It is Android so that limits it depending on your needs but I remember it being quite easy to use. The graphs look good and since it's programmable you can have it do pretty much anything you want.
It's unclear from your post if you just want one specific graph that you can do yourself or if you want a more general solution that you intend to use somewhere or even if you want the graph to be in some other project. For your own personal graph, for your own interest I would just use something basic like Office/Open Office or the equivalent depending on your OS/device.
