Email report task : fix bad var reference
DATE_END var was not set, because of a bad var name used ..  /
DATE_START was set with the following String : DATE_START: '(day_before {current timestamp})'
Daily report task  : using *milli*seconds to set env var will help
+ log process.env if asked to (process.env.NODE_DEBUG.match(/jira/))
Use a debug() function

To log only when process.env.NODE_DEBUG.match(/jira/)
DATE_START & DATE_END env vars are String and need to be casted as Number

Otherwise, this leads to
var ts = new Date(String); --> Invalid Date