Implement new calendar

[Process-ing]

Closes #1275

Review checklist

• Terms and conditions reflect the current change
• Contains enough appropriate tests
• If aimed at production, writes a new summary in whatsnew/whatsnew-pt-PT
• Properly adds an entry in changelog.md with the change
• If PR includes UI updates/additions, its description has screenshots
• Behavior is as expected
• Clean, well-structured code

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 12%. Comparing base (a4048ba) to head (b784754).
Report is 30 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff           @@
##           develop   #1372   +/-   ##
=======================================
+ Coverage       12%     12%   +1%     
=======================================
  Files          265     265           
  Lines         7356    7382   +26     
=======================================
+ Hits           815     819    +4     
- Misses        6541    6563   +22     

[DGoiana]

Good job here 🚀