Calendar: fix selecting dates in previous and next month

[jakobe]

Which issue does this PR close?

This PR closes #3451

What is the new behavior?

Updates the view to reflect the newly selected active month.

Does this PR introduce a breaking change?

• [ ] Yes
• [x] No

Are there any additional context?

Checklist:

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Review

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When the pull request has been approved it will be merged to develop by Team Kirby.