Recently, a user on Facebook asked this question:
can i create a 'due today' smart calendar for only selected calendars? i have calendars for various projects at work and at home and i would like to separate them based on work and home.
My initial response was to say "Nope, can't be done. You can create a smart calendar based on a search in All; or based on a search in a single calendar. You can't create a smart calendar based on a search of a subset (2 or more) of your calendars."
I offered a couple of alternatives that still weren't quite what Clayton was looking for, but let the question simmer at the back of my head for a while. Eventually, I came up with a workaround that made him really happy, and that I think worth sharing here. It does make one big assumption: that you don't much refer to the All calendar, and mainly "live" in Today.
(1) Create one or more calendars that will hold your work tasks. Make each of them visible in All, but NOT visible in Today.
(2) Create one or more calendars that will hold your home tasks. Make each of them visible in Today, but NOT visible in All.
Now, only tasks in your home calendars will appear in Today, and only tasks in your work calendars will appear in All.
(3) The final step is to go to the All calendar, which will display ONLY the tasks from your work calendars (because of step 1). Do a date range search, specifying Coming 1 day. Save the search. This will actually grab today and tomorrow, which I guess makes a certain amount of sense. When you save this search, call the new calendar something like "Work Today". You can't rename the default Today calendar, but it shouldn't take you long to internalize that it's for home tasks. "Work Today" will contain your work tasks due today and tomorrow, and "Today" will contain your home tasks due today.
If you try this, you can always swap the order of things and have your work tasks visible in Today and your home tasks visible in All -- it really doesn't make a difference which way you order things.
One thing to keep in mind: other than via the Today calendar, you will not have a way to view combined future events for the calendars you've chosen not to be visible in All -- if you want to see future events for those calendars, you will have to view the calendars individually. Because of this, best to construct things so the set with the smallest number of calendars appears in Today, and the set with the largest number of calendars appears in All (and the new smart search calendar).
I'm sure this is clear as mud - happy to answer questions.