Enter data with "json?time" command

In some case I need to enter manually many data that have not been recorded. For that I want to use the command "http://localhost/emoncms/input/post.json?time=1421995800&node=2&csv=xxx" for all the missings values. It doesn't work since I have only the 1st value recorded by this way. (I see only one value in the "RawData Graph")

Could you tell me if it is the correct way to do it or if I don't do things correctly ?

Thank you