From the Towns, Villages and Cities Wikia

After every addition of notable content for a place (and/or its subsidiary pages): if the place is not already listed on the Main Page for the latest month, someone should update by:

1. Adding a new month if the clock has ticked over to it - see below
2. Checking the latest month (using http://cities.wikia.com/index.php?title=Special:Recentchanges&days=32&limit=1500) and editing its article page - listed below here
3. Removing from the bottom list in that block on the Main Page (the "virtually neglected for several months" pages) the names of any places that appear in any of the recent months on display

To add a new month:

1. Update Main Page by adding a section for it above the previous month - just copy previous month's block and change month (and year if necessary) in two places.
2. If page not yet created (below here), create it, in one of two ways:
   1. going to another month, copying all, then editing your address bar to change the month/year, hitting "Enter", and editing to delete the placenames and change the "0712" or whatever
   2. seeing project:Edits by month - model page to make a copy for new month and making the small adjustments necessary, following the comments on the page
3. Then (within a few days) decide whether the oldest month shown should be removed. Three or four months should ideally be about enough, but with very few recent additions it won't hurt to leave a year's worth in place. If it should go, add its places to the bottom list (the "virtually neglected for several months" pages) except if they have appeared since. (If short of time, add them all anyway; and someone can purge the list later.)