dzl_g_date_time_format_for_display code looks odd
Everything that is more then 1½ hours and less then 48 hours ago is displayed as "Yesterday"?
else if (diff < (60 * 90))
return g_strdup (_("An hour ago"));
else if (diff < (60 * 60 * 24 * 2))
return g_strdup (_("Yesterday"));https://gitlab.gnome.org/GNOME/libdazzle/-/blob/master/src/util/dzl-date-time.c