Here's the problem: you inherited a workbook, and you need to know which sheets have gone stale. Excel gives you no built-in way to see a sheet's last edit date. That's not a minor oversight, it's a fundamental gap in how traditional spreadsheets handle accountability. When you have to manually open every sheet and guess whether it's current, you're not managing data. You're auditing blind.
The user who posted this question is doing something smart. They're not asking for a workaround that requires them to touch every sheet. They're asking for a repeatable, automated solution, a one-off VBA macro to scan the workbook and an Excel function to keep it updated. That's the right instinct. A manual audit of fifteen sheets might take an hour. A manual audit of fifty sheets takes four hours, and you'll still miss something. The macro does it in seconds, and it does it consistently. That's not just efficiency; that's a shift from reactive data management to proactive oversight.
What this really reveals is the limitation of the spreadsheet as a static document. Every sheet in a workbook is treated as an independent canvas, with no shared awareness of what changed when. The user is asking for something that should be table stakes: a timestamped record of activity per sheet. Excel doesn't offer it, so they're building it themselves. That's the story of modern data work, users outgrowing the tool and innovating around its edges. The VBA approach works, but it's a patch. The deeper question is why we accept a tool that makes us write custom code just to answer "when was this last touched?"
For anyone managing a multi-sheet workbook, the practical takeaway is clear. Don't rely on memory or manual inspection. Build a lightweight audit system into your index sheet. A VBA macro that loops through each sheet, checks the `LastChange` property or parses the file metadata, and writes the date into a table is straightforward to implement. Pair it with a `TODAY()`-based conditional format that flags anything older than six months, and you've turned a one-time headache into a living dashboard. The macro runs on demand; the function updates automatically. You stop guessing and start knowing.
The solution exists, and it works. The real opportunity is to stop treating this as a one-off fix and start asking what other blind spots your workbook has. If a sheet's last update date is invisible, what else is hidden? The macro is a start. The mindset, that your tools should answer your questions, not force you to hunt for them, is the transformation worth pursuing.