Blondie Watch
Based on context clues I think you can firmly conclude that the Bumsteads are currently living in the year 2015.
From Zippy the Pinhead:
After Griffith criticized Scott Adams’ comic Dilbert for being “a kind of childish, depleted shell of a once-vibrant medium,” Adams responded a year and half later on May 18, 1998, with a comic strip called Pippy the Ziphead, “cramming as much artwork in as possible so no one will notice there’s only one joke… [and] it’s on the reader.” Dilbert notes that the strip is “nothing but a clown with a small head who says random things” and Dogbert responds that he is “maintaining his artistic integrity by creating a comic that no one will enjoy.”
At this point in time Dilbert was at the height of its popularity, its characters were appearing in Office Depot commercials, and there was a TV series adaptation set to premiere the following year. Imagine having all that success and still being this petty.
Mallard Fillmore Watch
It’s wild that this can appear on the same page as Garfield