Pass duration to delay

Configuration
1

Making a script that adds a delay based on what’s passed in. Eg reminder for bedtimes are delayed. I would have a time trigger, then call this script with a duration eg 30min. So on sat they’d get 30min extra.

I get a duration in, but I don’t know how to turn that into a delay:

alias: Check Holiday Mode
description: Delay kids times if no school next day
fields:
  duration:
    name: duration
    description: Time to delay
    selector:
      duration: null
sequence:
  - if:
      - condition: or
        conditions:
          - condition: time
            weekday:
              - fri
              - sat
            before: "00:00:00"
            after: "00:00:00"
          - condition: state
            entity_id: input_boolean.holiday_mode
            state: "on"
    then:
      - delay:
          {{duration}}.something convert????????
mode: single

How do I fix this?