refactor: add and use parseDate

[vil02]

 know more

Describe your change:

As promissed, this PR adds a function parseDate.

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• All new JavaScript files are placed inside an existing directory.
• All filenames should use the UpperCamelCase (PascalCase) style. There should be no spaces in filenames.
  Example:UserProfile.js is allowed but userprofile.js,Userprofile.js,user-Profile.js,userProfile.js are not
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.07%. Comparing base (bd34e9f) to head (efeab6e).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1643   +/-   ##
=======================================
  Coverage   84.07%   84.07%           
=======================================
  Files         375      376    +1     
  Lines       19688    19694    +6     
  Branches     2913     2907    -6     
=======================================
+ Hits        16552    16558    +6     
  Misses       3136     3136           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[appgurueu]

Makes sense.

(Though probably these date-related functions should take "date" objects instead of strings in the first place to save them the (not very interesting) parsing.)