This little plugin allow customing the “date base” of date (month, year, day, etc.) archive page. For example, by default your blog’s monthly archive page’s permalink is like: “http://example.com/date/2010/05/”, with this plugin you can change the string “date” to others, just like the feature of changing permalink’s category base and tag base which is built in WordPress.
Note if your blog’s permalink structure is “/YYYY/mm/dd/post-slug/”, this plugin will not take effect and your blog’s permalink of date archive page would be “/YYYY/mm/”.