Hit a Dead End on a Quest

I found the following file - 2010-10-2523-03-37_timesheet_m.xlsx - on one of my EHDs. I attempted to open the file - because I didn't know what it was - and saw that it was password-protected. I don't remember the password as it was assigned to this file 4613 days (12 years, 7 months, 2 weeks, 4 days) ago. It could be a container for "useful" information; it could be a container for "unuseful" information. I don't know. I can't open the file.
I turned to Google. I found this video:

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and noticed that the video includes a link for "written instructions" so I clicked it: https://www.myonlinetraininghub.com/easily-remove-excel-password-protection. In the last section of this page, I read the following:

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I've reached the dead end on this quest. I will continue to look for another resource.