If i define a new environment variable using custom formatted version number, i am unable to pass that to the downstream job.

Steps:
1. In promote build, select manual promotion, Point to job number 2, then in action, trigger parameterized build and define a predefined param NEW_BUILD_VERSION=$NEW_BUILD_VERSION

2. in build environment, create a formatted version number
variable NEW_BUILD_VERSION as ${BUILD_YEAR}${BUILD_MONTH, XX}${BUILD_DAY, XX}-${BUILDS_TODAY}

In downstream job i just have the shell script
echo ${NEW_BUILD_VERSION}

Observed behavior: in upstream job, i am able to see the new environment variable. In downstream job the script gets a blank version number

Desired behvaior: downstream job gets the build version number

What am i missing? is this a bug or do i need to do something more?