In 0.25 luckily it’s added 
timer_off_lrm: alias: "Ceiling light living room timer" sequence: - delay: minutes: '{{ input_slider.slider1 }}' - service: homeassistant.turn_off data: entity_id: switch.light_dining_table
and
delay: '00:{{ input_slider.slider1 }}:00'
Doesn’t work for me…
Am I missing something?