Populate field with dynamic value

Elastic Stack Elasticsearch
1

i have a requirement to show the remaining days for an expiration days, like if record expire in 100 days we should be able to give a field back saying expire in 99 days 98 days..
my questions is how do i generate the a record with this dynamic value in it

Thanks,
Tijo

2

Take a look at script fields.

3

Thanks spinscale