While, technically, there is no established canon in the Get Fuzzy universe, we, like other wikis, have our own rules as to what is and isn't considered to be canon:
Darby Conley's word is final!
If Darby Conley (the strip's creator) himself states something regarding continuity, we must follow it strictly, as he has the creative rights.
The strip will always come first.
If there is ever any kind of official spin-off material, the original comic strip, being the original source material, will still be the highest level of canon (below Darb, that is).
Seriously, no fanfic. If there is enough demand for it, a fan fiction wiki will be created.
We use real world dates in our articles (I.E. June 25, 2017), and it is assumed that the events of a strip take place on the day that the strip was published. The exception to this is if certain events of a storyline obviously take place on the same day, in which they are assumed to take place on the day of the first strip that they appear in.
We believe that any point where the strip breaks the fourth wall (I.E. Characters talking to the readers) is not canon, as well as strips about its production.
Any characters, locations, events and/or storylines that have been rejected or cut from the strip are considered non-canon.