Challenge 2: A Scheduled 8am Email With No File Open — Solution Walkthrough

Why this is possible with Apps Script:

Apps Script runs on Google's own servers, in the cloud, entirely
independent of whether anyone has the spreadsheet open in a browser
anywhere. A time-based trigger (set up via the Apps Script editor's
own Triggers panel, choosing a time-driven trigger for a specific
daily time) tells Google's infrastructure to execute the script's
function automatically at 8am every day, regardless of whether the
Sheet is open, closed, or nobody has looked at it in days. The script
runs on the server side, on Google's own schedule, not inside anyone's
browser session.

Why an equivalent VBA macro couldn't do this in Excel:

VBA macros run locally, inside the actual Excel application process
on someone's own computer — there is no equivalent of a VBA macro
executing "in the cloud" independent of the desktop application being
open. For a VBA macro to run at 8am automatically, the workbook would
need to already be open in a running copy of Excel at that exact
moment (potentially combined with a separate operating-system-level
scheduling tool to open Excel and run a macro), which is a
fundamentally different, more fragile requirement than Apps Script's
own server-side, always-available scheduling.

WHY THIS WORKS AS AN ANSWER
------------------------------
This is a direct, concrete illustration of this chapter's own "what
Apps Script can do that the others can't" section — the cloud-native
execution model isn't just a different way of writing the same kind
of automation, it enables genuinely new capabilities (running with
nothing open at all) that a locally-running macro language cannot
replicate without external help.