I need exact time range for snapshot/indices, not ages.
I'm not sure I follow. If you mean you need to snapshot indices between x days old and y days old, then Curator allows you to do this by using 2 age filters, 1 set to filter older than x days, and 1 set to filter younger than y days old.
Sorry for the misunderstanding.
I need snapshot from (For example) July 1st to July 31st in early August; and (for example) Sept. 1st to Sept 30th in early October.
I cannot use age older/younger because all month are different (some month have 30 days and some have 31 days). The script will run in an automatic system which should work against all monthly snapshot. So changing config file will not work.
Furthermore, this will usually run around 2nd day of each month to take previous month's (1 to 30/31) indices snapshot (ONLY). But this script may sometime run on 5th or later due to various problem. So either age-day and age-month will not work based on our dry-run exam last week.
So I am wondering if there are a filter type that allow us to mark time range to monthly.