[filebeat panw module] set timezone when hostname field contains keyword

[gadelkareem (Waleed Gadelkareem)]

How can I set timezone to ex EST when hostname field contains us-east-1?

I tried something like this but it does not work:

  - date:
      if: "observer.hostname.toLowerCase().contains('useast') "
      field: "_temp_.generated_time"
      target_field: "_temp_.generated_time"
      timezone: "-05:00"
      formats:
        - "yyyy/MM/dd HH:mm:ss"