Creating snapshot every six months

Elastic Stack Elasticsearch
1

Hi,
I have lot of records in only one index so I want to create snapshots backup of index every six months and point those to different index pattern so that I can have different dashboards for every six months and one dashboard for current six months.
First I have to schedule snapshot to every six moths
found some solution to that using SLM

PUT /_slm/policy/daily-snapshots
{
  "schedule": "0 30 1 * * ?", 
  "name": "<daily-snap-{now/d}>", 
  "repository": "my_repository", 
  "config": { 
    "indices": ["data-*", "important"], 
    "ignore_unavailable": false,
    "include_global_state": false
  },
  "retention": { 
    "expire_after": "30d", 
    "min_count": 5, 
    "max_count": 50 
  }
}

Is above query and "schedule" Cron Expression as per every six months
SECOND THING IS
want to create separate index as per snapshot ?
Is it available in version 7.4 or not?

2

No, it was released in 7.5 - Take a snapshot of one or more indices | Elasticsearch Guide [7.5] | Elastic. However anything before 7.10 is EOL, and no longer supported. You should really be looking at 7.17 as the latest 7.X release.

It's not clear what you mean here.