Just to update for anyone who is interested in doing the same, my question was incorrect because number.set.value does not work with number.dishwasher_delay bosch home connect integration. My current working code using the cheapest_energy_hours macro is below:
action: home_connect.set_program_and_options
data:
device_id: <device id>
affects_to: active_program
b_s_h_common_option_start_in_relative: >-
{% from 'cheapest_energy_hours.jinja' import cheapest_energy_hours %} {{
(cheapest_energy_hours(sensor='sensor.nordpool_electricity_prices',
hours=5, start='20:00', end='07:00', look_ahead=true,
include_tomorrow=true) | as_datetime - now()).total_seconds() | int }}
program: dishcare_dishwasher_program_eco_50
with inspiration from Home connect - Bosch dishwasher delayed start - #6 by tboss