Sorry for the delay

I think it would be actually better to use timestamp in epoch milliseconds (as a Long Java type) for request/response times.

Then you can use freemarker ?number_to_datetime function to pretty print date. https://freemarker.apache.org/docs/ref_builtins_expert.html#ref_builtin_numToDate

That will add possibility to use different time representation for users with custom request/response templates

Then, it would be nice to have a possibility to set request/response timings by passing value to the builder