Timestamp Microservice in API'S & Microservices

I am unable to pass the 3rd use case in the User stories. Those are
1 It should handle an empty date parameter, and return the current time in unix format.
2 It should handle an empty date parameter, and return the current time in UTC format.
I tried different scenarios, i am still unable to pass the 2 test cases. I just want to know what is the issue. Here i am attaching my implementation.