Gagan Deep Singh

Plugin handles the permalink changed due to changes in the post date when post date is used in the permalink structure. 
Tries to correct any malformed permalinks by trying to find the post in case of 404(File not found) header. 
It is just plug and play, activate it and it starts working, no configuration required.

Post Date Change Redirection

Saved us

Handles the changes in the permalink due to change in post date by providing 301 redirection

djm56

Micro Site Care: Post Last Updated Date adds a last-updated date label to your posts and pages. It is lightweight, uses no JavaScript, and integrates cleanly with any theme.
Key features:
<ul>
<li>Show the last-updated date automatically before content, after content, or in both positions.</li>
<li>Set placement to Manual and use the template tag in your theme for full control over where the label appears.</li>
<li>Customise the label text with a flexible template — use <code>%s</code> to insert the date, or omit it to show a static label.</li>
<li>Choose between the WordPress site date format or a custom PHP date format string.</li>
<li>Optionally suppress the label when the modified date matches the publish date (suppress unchanged posts).</li>
<li>Target specific post types, or exclude selected post types from an all-types baseline.</li>
<li>Clean HTML5 <code><time></code> element output with an ISO 8601 <code>datetime</code> attribute for SEO and screen readers.</li>
<li>Developer-friendly: four filter hooks to customise visibility, label, CSS classes, and final HTML output.</li>
<li>Compatible with MSC Post Last Updated Date Pro for relative dates, style presets, per-post overrides, and shortcodes.</li>
</ul>

Micro Site Care: Post Last Updated Date

Display and control the last-updated date for your WordPress posts and pages, with flexible placement and label options.

Post Date Change Redirection vs Micro Site Care: Post Last Updated Date