- sensor:
      - name: "hodinovka"
        unique_id: HODINOVKA
        state: >
          {# Define your intervals here as tuples (hour starting the interval, hour ending the interval (excluded)) #}
          {% set intervals = [
            (1, 8),
            (8, 16),
            (16, 24),
          ] %}

          {# We need to use namespace so we can write into it in inner cycle #}
          {% set min = namespace(price=None, dt=None, cheapest_hours=[]) %}
          {% set cheapest_hours = [] %}


          {% for interval in intervals %}
            {# Reset min price from previous runs #}
            {% set min.price = None %}

            {# Go through all the hours in the interval (end excluded) and find the hour with lowest price #}
            {% for i in range(interval[0], interval[1]) %}
            {# Get datetime of current hour in current interval #}
            {% set hour_dt = now().replace(hour=i, minute=0, second=0, microsecond=0) %}

            {# Get value for that hour #}
            {% set value = states.sensor.current_spot_electricity_hour_order.attributes.get(hour_dt.isoformat()) %}

            {# Skip if not found #}
            {% if value is not defined %}
              {% break %}
            {% endif %}

            {# value is tuple (order, price), we'll use the price #}
            {% set price = value[1] %}

            {# Min price is not set or is higher than price of current hour => store the min price and hour #}
            {% if min.price is none or price < min.price %}
              {% set min.price = price %}
              {% set min.dt = hour_dt %}
              {% endif %}
            {% endfor %}

            {# Store cheapest hour in current interval #}
            {% set min.cheapest_hours = min.cheapest_hours + [min.dt.hour] %}
          {% endfor %}

          {# use this to get the cheapest hours #}
          {# {{ min.cheapest_hours }} #}

          {# return True if current hour is in the cheapest hour of any interval #}
          {{ now().hour in min.cheapest_hours }}