{"json_modified": "2016-03-28T08:29:02.989791", "uuid": "7b30885e-5894-4fe5-aa25-3decc8919c26", "title": "PerformanceTiming.unloadEventStart", "url": "/en-US/docs/Web/API/PerformanceTiming/unloadEventStart", "tags": ["PerformanceTiming", "Property", "Navigation Timing", "API", "Read-only"], "translations": [], "modified": "2015-02-22T10:51:02", "label": "PerformanceTiming.unloadEventStart", "localization_tags": [], "locale": "en-US", "id": 81397, "last_edit": "2015-02-22T10:49:36", "summary": "The <code><strong>PerformanceTiming</strong></code><strong><code>.unloadEventStart</code></strong> read-only property returns an <code>unsigned long long</code> representing the moment, in miliseconds since the UNIX epoch, the <code><a href=\"/en-US/docs/Web/Events/unload\" title=\"/en-US/docs/Web/Events/unload\">unload</a></code> event has been thrown. If there is no previous document, or if the previous document, or one of the needed redirects, is not of the same origin, the value returned is <code>0</code>.", "sections": [{"id": "Quick_Links", "title": null}, {"id": "Summary", "title": "Summary"}, {"id": "Syntax", "title": "Syntax"}, {"id": "Specifications", "title": "Specifications"}, {"id": "Browser_compatibility", "title": "Browser compatibility"}, {"id": "See_also", "title": "See also"}], "slug": "Web/API/PerformanceTiming/unloadEventStart", "review_tags": []}