How Kopia retention works?

I would need to apply a retention policy as follow:

  • 1 snapshot by day for the last 4 days
  • 1 snapshot by weekly
  • 1 snapshot by monthly

I have a cron job to create snapshot everyday, but I noticed the weekly tag is always on the latest snapshot.

How does the retention work? daily snapshot will be purged after 4 days, right? Then, which snapshot will be kept for a week or a month?