[8.15] fix(slo): Use correct calendar period (#199873) (#200067)

# Backport

This will backport the following commits from `main` to `8.15`:
- [fix(slo): Use correct calendar period
(#199873)](#199873)

<!--- Backport version: 9.4.3 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

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Use correct calendar period
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Use correct calendar period
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Use correct calendar period
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BACKPORT-->

Co-authored-by: Kevin Delemme <[email protected]>