I don’t know if you ever figured out how to use now() ?
If not, then here is an example!
data_template:
brightness: >
{% if ('sun.sun', 'above_horizon') and now().hour >= 10 and now().hour < 18 %}
255
{% else %}
56
{% endif %}
This will set the brightness of a given light to 255 between 10:00 and 18:00 and else it will be 56.
Cheers!