Timestamp microservice

Test this API:
Note that the input must be either blank or a string or number recognized by new Date() to get a meaningful result.
API output:

View the source on GitHub or Glitch.

I created this app as a requirement for my freeCodeCamp APIs and Microservices Certification, using Node.js and Express. The above front end API test also uses Bootstrap, jQuery, and highlight.js. The API fulfills the following user stories:

  1. The API endpoint is GET [project_url]/api/timestamp/:date_string?
  2. A date string is valid if can be successfully parsed by new Date(date_string).
    • Note that the unix timestamp needs to be an integer (not a string) specifying milliseconds.
    • In our test we will use date strings compliant with ISO-8601 (e.g. "2016-11-20") because this will ensure an UTC timestamp.
  3. If the date string is empty it should be equivalent to trigger new Date(), i.e. the service uses the current timestamp.
  4. If the date string is valid the api returns a JSON having the structure {"unix": <date.getTime()>, "utc" : <date.toUTCString()>} e.g. {"unix": 1479663089000, "utc": "Sun, 20 Nov 2016 17:31:29 GMT"}
  5. If the date string is invalid the api returns {"error": "Invalid Date"}.