fix date filters in config parsing

[alexgoedeke]

Fix date filters

🗣 Description

This pull request fixes the parsing of the date filters in the config file.

💭 Motivation and context

There is a bug in the parsing of the config file regards the date filter.

🧪 Testing

I dumped UAL and SignIn logs on an azure test tenant with an E5 license.

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated
  to reflect the changes in this PR.

✅ Pre-merge checklist

• Revert dependencies to default branches.
• Finalize version.

✅ Post-merge checklist

• Create a release.