gistfile1.yml

---
- name: Group by Distribution
  hosts: all
  tasks:
    - group_by: key={{ansible_distribution}}

- name: Set Time Zone
  hosts: Ubuntu
  gather_facts: False
  vars:
  - my_zone: 'America/New_York'

  tasks:
    - name: check current timezone
      shell: cat /etc/timezone
      register: current_zone

    - name: Set timezone variables
      copy: content={{my_zone}}
            dest=/etc/timezone
            owner=root
            group=root
            mode=0644
            backup=yes
      when: current_zone.stdout != my_zone
      notify:
        - update timezone
  handlers:
    - name: update timezone
      command: dpkg-reconfigure --frontend noninteractive tzdata

Doesn't work. The ansible part works, but "dpkg-reconfigure --frontend noninteractive tzdata" will reset it to what it was before.

I added this task here

• name: ensure correct timezone link is set
  file:
  src: '/usr/share/zoneinfo/{{my_zone}}'
  dest: /etc/localtime
  owner: root
  group: root
  state: link

After that, the handler will do the right thing.

here is my solution

• name: Check current timezone
  shell: cat /etc/timezone
  register: current_timezone
  changed_when: false

• name: Set Timezone
  timezone:
  name: America/Chicago
  when: current_timezone.stdout != "America/Chicago"