https://www.w3schools.com/jsrEF/prop_doc_lastmodified.asp
HTML DOM Document lastModified Property
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html domdocumentlastmodifiedproperty
https://www.c-sharpcorner.com/blogs/lastmodified-property-in-javascript1
lastModified property in javascript
lastModified property is used to get the date and time when the document is last modified.
property inlastmodifiedjavascript