Sending historical data to Graphite DB

Hi - I’m using Grafana Cloud with Graphite
I’m sending metrics using carbon-relay-ng
I would like to know what the cutoff for sending ‘old’ data is - i.e. if I send old metrics with a timestamp in the past, what is the cutoff? Can I send data that is 30 minutes old, 30 seconds?
For example, I want to send data from my LinkTap - but its API only has the last 30 days’ history - I don’t believe that data will be loaded.
Can someone tell me the ‘cut-off’? Can I configure it?
Thank you