{{- $pages := .pages | default (slice) -}}
{{- $filtered := slice -}}

{{- range $page := $pages -}}
  {{- if isset $page.Params "date" -}}
    {{- $frontmatter := "" -}}
    {{- with $page.File -}}
      {{- $source := readFile (printf "content/%s" .Path) -}}
      {{- $frontmatter = delimit (findRE `(?s)^---\r?\n.*?\r?\n---` $source 1) "" -}}
    {{- end -}}
    {{- if gt (len (findRE `(?m)^date:\s*['"]?\d{4}-\d{2}-\d{2}[ T]\d{2}:\d{2}:\d{2}['"]?\s*$` $frontmatter 1)) 0 -}}
      {{- $filtered = $filtered | append $page -}}
    {{- end -}}
  {{- end -}}
{{- end -}}

{{- return $filtered -}}