why my date variable not change in global variable postman

Question

i had set year,month,date,etc in global. it work when i created this. but when after 3 month. the variable is not change. I think it's because of Momentjs but when i try new Date() it same. not change anymore

this my pre-script for set the global variables

This image shows that the postman global variable is not accurate

i am trying to create a dynamic global variable in postman, and use it for variable in request