Not able to store metrics in graphite with previous time stamps

I have configured graphite on 9'th Jan 2019 with the below carbon configurations.

[garbage_collection]
pattern = garbageCollections$
retentions = 10s:30d

I understand the meaning of the above configurations. The retentions line is saying that each data point represents 10 seconds, and we want to keep enough data points so that they add up to 30 days of data.

As retention time is 30 days my expectation is I can store data from 19'th Dec 2018 to 17'th Jan 2019 (Today). However when I tried feeding data points from 19'th Dec 2018 to 9'th Jan 2019 but graphite is not able to store it.

Will graphite only store data from 9'th Jan 2019?

Let me know if any further details are required.