Question: Where exactly is Whoville located? And what year is the movie meant to take place?
Answer: According to the introduction, Whoville is located on a snowflake. Therefore they don't keep time like we do.
Question: In the beginning, there is a watchman that announces "Another minute closer to Christmas!" as each minute ticks off a countdown clock. Assuming that each panel (days, hours minutes) is on a revolving wheel of some sort, how can the three wheels work correctly in such close proximity to each other? Granted, only the minutes part moves for the sake of the story, but it still begs the question.
Answer: By machine.
The clock in "How the Grinch Stole Christmas" is designed for cinematic effect; a real-world counterpart would rely on precise gearing and engineering to allow three separate wheels to operate in close proximity without interfering with each other. The key would be in the gear ratios and the alignment of the gears to ensure smooth operation of each panel.
Answer: Then why does it appear as a tiny speck in Horton Hears A Who?
In "Horton Hears a Who", both the book and the animated film, the speck of dust lands on a clover. In the 2000 Grinch film, the speck of dust has now landed on a snowflake because it's winter time. It should be noted that it's only the 2000 Grinch film that has Whoville as a speck similar to Whoville in "Horton Hears a Who." In the book and other adaptations, Whoville and the Whos are normal sized and probably located somewhere in Massachusetts.
Bishop73
Where are you getting Massachusetts from?
Brian Katcher
Dr. Suess was born in Springfield, MA and there are some that claim the drawings in the book are similar to Easthampton, MA and Mt. Tom (although others say it's La Jolla and Mt. Soledad in California). Residence of Easthampton put on an annual "Whobalation" to celebrate the legend Whoville is based on them.
Bishop73