[ryandrake]

I don't even know why the 365 number is so important. I mean, it probably has something to do with there being 365 days in 3 out of 4 years, but what makes that significant to a word processor or spreadsheet? It's as if Google were to rename their product "Search 60" because there are 60 minutes in an hour. So what?

Microsoft's brand names never made a whole lot of sense--they're just continuing the tradition.

[amenhotep]

It's an artifact of the transition away from year-based releases to a subscription. Customers were used to Office 95, Office 98, Office 2003, etc. 365 sort of matches that pattern, so customers aren't excessively disgruntled, while signalling that there's a "release" on every day of the year, it's constantly up to date.

And I guess they've just kept it since even though it's not really necessary any more.