Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
read-only property returns an
unsigned long long representing the moment in
time (in milliseconds since the UNIX epoch) when the browser received the first byte of
the response from the server, cache, or local resource.
unsigned long long.
BCD tables only load in the browser
PerformanceTiminginterface it belongs to.