Date-based numbering from a date field inside a structure field

Kirby 2 Questions 🤔
1

Is it possible to address a date field inside a structure field when defining a date-based numbering blueprint? Something like:

pages:
  num: 
    mode: date
    field: dates.event_day[0]
    format: Ymd

My structure field is going to contain several date entries, but I’d like to use the first one, hence the (lousy) dates.event_day[0] attempt… a long shot indeed :blush:

I thought about the “type: query” option… but not sure if (or how) it can be used in the blueprint’s pages settings

This is the parent “/events” blueprint:

title: Events
files: false
pages:
  template: event 
  num: 
    mode: date
    field: dates.event_day[0]
    format: Ymd

fields:
  title:
    label: Title
    type:  text
  sobre:
    label: Text
    type:  textarea

And here’s the dates structure field from the child blueprint “/events/event”

... 

  dates:
    label: Schedule 
    type: structure 
    required: true 

    entry: >
      Date: {{event_day}}. From {{time_start}}h to {{time_end}}h.
      
    fields:

      event_day:
        label: Event's date
        type: date
        format: DD/MM/YYYY

      time_start:
        label: Start time
        type: time
        default: 08:00
        interval: 15
        width: 1/2

      time_end:
        label: End time
        type: time
        default: 18:00
        interval: 15
        width: 1/2
...
2

This is not possible and you can’t use a query here either. I have no idea if it might be possible to create a custom field that gets the date from the first entry of the structure field …