Dion

UsageDD allows administrators to monitor the resource usage of their WordPress installation. It will add a small box at the bottom center of each page, only visible to administrators, that displays the number of MySQL queries, the amount of memory used by the page’s code, and if you are using a compatible webserver (most are compatible), the “time to first byte” (TTFB) and the time required to generate the full page. TTFB is used by Google for page-ranking purposes, and it will be the first of the two displayed.
You can use the display to determine if your site has too many plugins loaded, if your theme is too “heavy”, or if something is wrong on your server. The plugin itself uses virtually no resources and should be compatible with every theme and plugin that outputs HTML.
Support is available in our <a href="https://forum.dion-designs.com/f35/usagedd-support/" rel="nofollow ugc">dedicated support area</a>. Support questions posted on wordpress.org may go unanswered for an extended period of time.

UsageDD

UsageDD allows administrators to monitor the resource usage of their WordPress installation.

Resource Calendar enables the reservation of resources. 
Resource Calendar will be useful for a need for displaying the availability of a resource.

Resource Calendar

Resource Calendar enables the reservation of resources.

UsageDD vs Resource Calendar