{{ $date := .Date.Format "02.01.2006" }}
{{ $lastmod := .Lastmod.Format "02.01.2006" }}

{{- if ne $lastmod $date -}}
<span title={{ .Lastmod }}><i>Last updated on {{ .Lastmod | time.Format (default "January 2, 2006" site.Params.DateFormat) }}</i></span>
{{- end }}