Philately815,
Easy answer is yes!
As an example of what revcollector mentioned, I am a calendar collector in that I have calendar pages from 1862 - 1902 and look to find a canx date for each day in that period.
Here in Albuquerque we have at least a few collectors that have specific Civil War dates they look for revenue stamps with those dates. They write up the event (battle, assassination, etc.), and show a canceled stamp for that date.
I started as a cheap way to occupy myself at shows when I couldn't find other things for my collections. I call them distractor collections (and I have several), but my calendar collections were started in 1996 and I am still searching!
Most calendar collectors look to upgrade manuscript canx to better canx when they find them. A nice SOTN canx looks better than chicken scratch

Here is an example of a page (Jan, 1867):
