How to see shard group duration of a bucket

Hi, I have a bucket where I store data that a sensor send every 10 seconds (influx 2.5). On the other hand, I have another bucket in which through a task, I save the reduced measures (I save the average of the measures of the first deposit every 30 minutes).
I’ve given the second bucket an infinite retention policy, and the first bucket, which currently has infinite retention, I want to assign a one-month retention policy.
To do this, I think you would need to know what is the shard group duration of the first bucket, and if necessary, change it. Where can I see this data, and how can it be changed?

Hello @s118,
The following documentation might be helpful to you:

And to view retention policies you can see:

Does that help?
Thank you.

Just one thing. If I reduce the retention, does the shard group duration automatically decrease?
For example, if I put a retention of 6 months, will the shard group duration become 1 day?