Pages listed that are of the form Wikipedia:Cleanup/<MONTH> (such as Wikipedia:Cleanup/June) are ignored for counting purposes, as they are not truly in need of cleanup, but rather information pages about what needs cleanup.
Bot internals
The bot starts at Category:Cleanup by month and collects the categories (listed under the Subcategories section on that page), named "Cleanup from {MONTH} {YEAR}", that contain pages needing cleanup.
Each category page is inspected, and the number of pages in that category is calculated:
The bot looks for the string "There are ## pages in this section of this category." at the top of the "Pages in category..." section on each category page, and keeps track of that number.
The bot will follow "(next 200)" links on category pages in order to get the complete count for the category.
The bot will immediately abort if a count of 0 is returned for any category (as this is an impossibility and means that the bot had trouble parsing a page, or, more likely, timed out while trying to do so).
If the bot successfully retrieved information from each category, it will pull the total number of articles from Special:Statistics.
The bot will then format the information gleaned into wikicode, and .
The bot keeps track of the elapsed time and number of pages processed. On average, a successful run takes about three minutes, and processes less than one hundred pages.