begin options
{% if time_units is defined %}  time_units {{time_units}}
{% endif %}
{%- if start_date_time is defined %}  start_date_time {{start_date_time}}
{% endif -%}
end options

begin dimensions
  nper {{nper}}
end dimensions

begin perioddata
{% for perlen, nstp, tsmult in perioddata %}  {{perlen}} {{nstp}} {{tsmult}}
{% endfor -%}
end perioddata
