How can I calculate a duration from start and end time

[kontango-bot]

here's my taskfile:

vars:
  start_time: "{{ now }}"

tasks:
  test:
    cmds:
      - sleep 5
      - task: end_timer
      - echo "Done."

  end_timer:
    cmds:
      - "echo Start time: {{ .start_time }}"
      - "echo End time: {{ now }}"
      - "echo Duration: {{ now.Sub mustToDate(.start_time) }}"

This is invalid syntax, and i've tried a few other things (e.g. without parens) that also seem to be invalid.

Part of the problem is that .start_time gets converted to a string, which is not suprising. I'm not sure how to convert it back into a date before passing it into now.Sub. Or, if there is a way to store now without converting it to a string, that would be ideal.

[kontango-bot]

It seems that vars are evaluated when they are called, so i don't think this approach will work either way.

[kontango-bot]

This is what I ended up with:

vars:
  start_time: { sh: date +%s }

tasks:
  test:
    cmds:
      - sleep 5
      - task: end_timer
      - echo "Done."

  end_timer:
    cmds:
      - "echo Duration: {{ .duration | duration }}"
    vars:
      duration: { sh: "echo $(( $(date +%s) - {{ .start_time }} ))" }