This template will return true on the 4th sunday of every month:
{{(now().strftime("%d")|int>=22) and (now().strftime("%d")|int <=28) and (now().strftime("%w")|int==0)}}
And here it is in a sample automation that turns a switch on at sunrise the 4th Sunday of every month.
- alias: 4thSundaySwitch
trigger:
- platform: sun
event: sunrise
condition:
condition: template
value_template : '{{(now().strftime("%d")|int>=22) and (now().strftime("%d")|int <=28) and (now().strftime("%w")|int==0)}}'
action:
- service: switch.turn_on
entity_id : switch.sundayswitch