The variables in this diagram are defined as follows:

Table 1. Timing Values

Variable	Description
start_time	The date and time the user requests a page (the user clicks on a link). This value is set by hooking into the beforeunload event of the previous page. The beforeunload event is not properly supported by WebKit browsers, which is why the client timings are not supported on Safari or Chrome.
load_time	The date and time that the current page starts loading in the browser. This value is set by an inline javascript that runs as the first script in the HTML body.
server_time	The time in ms spent by the server processing the transaction. The server reports this value to the client.
load_completion_time	The date and time that the page is fully rendered in the browser. This operation is performed as the last script on the page and identifies the time the page completed loading.

The following timings are reported at the bottom right of many forms and lists:

Table 2. Timing Values

Label	Element	Description	Calculation
Response Time	client_response_time	Calculates the overall time to deliver the page by subtracting the time the user requests the page from the time the page is fully rendered in the browser.	load_completion_time - start_time
Server Time	client_server_time	This is the time the server takes to process the transaction.	server_time
Network Time	client_network_time	Calculates the time the network takes to process the request by subtracting the time of the user's request from the time the page starts loading in the browser, and then subtracting the server processing time.	load_time - start_time - server_time
Browser Time	browser_time	Calculates the time the browser takes to deliver the page by subtracting the time the page is fully rendered from the time the page starts loading in the browser.	load_completion_time - load_time