Combine graphs, but one graph is monitored not from t=0

[Michiel_XS]

Hi,

Via cacti I generate some traffic graph and I combine them with a template to one traffic graph.

But when I add a graph later (at timestamp T), the total traffic graph is only displaying data from the timestamp (> T) I created the latest graph.

How can I say to rrdtool that it should display the data correctly and exclude the latest graph until timestamp T?

Thanks!