Files of sender and receiver are combined, thus it is important to have
a timestamp that is relative to common anchor, UNIX_EPOCH in this case

Using macros allows the macro invocation with xlap disabled and without
definitions generated from the xlap.yml.

This means xlap is disabled by default

variable

This version uses hardcoded values ,doesn't print all the header
fields and uses indices in the code to refer to the correct timestamp
but it is a first working version that gives the correct output.