How do I get the Current time in milliSeconds in a Shell script in buildroot environment?

Question

MYENV=$(date +"%s%N")
printf "Time:: %s\n" "$MYENV"

or

MYENV1=$(date +"%T%N")
printf "Time:: %s\n" "$MYENV1"

I tried above methods, they do work in regular linux but not working in buildroot.

1606718041%N is the output being printed. What does this mean? Is this a specific format? How to decode this? (If I'm not wrong this is the time since epoch, correct ?)