Correct. I like functions and was glad you posted about it. I was just writing something up on that...
While the Year component may not be as efficient, it can be used for Month, Day of Month, and (possibly) Day of Week. For example
If you want all items put out in a particular Month (January in the example):
strftime('%m', I.CoverDate) = '01'
You can also constrain it to a Year range (Month January between 2010 and 2019):
strftime('%m', I.CoverDate) = '01' and I.CoverDate Between '2010-01-01' and '2019-01-01'
The Day of Month and Day of Week are probably most useful for Street Date as Cover Dates normally have Day of 1 (with bi-monthly or weekly being some exceptions)
Not sure if they are useful or not but if you need them:
All items with a Day of '15':
strftime('%d', I.StreetDate) = '15'
All items that came out on a Wednesday (Sunday = 0, Saturday = 6):
strftime('%w', I.StreetDate) = '3'
NOTE: the % value is case-sensitive. %m works. %M does not.