Each month, the U.S. Department of State issues the Visa Bulletin. When the bulletin is issued, usually mid-month, it will provide information that will take effect on the first day of the following month. (e.g., on 09-09-2010, the State Department released the dates effective as of 10-1-2010). Depending on the availability of immigrant visas, the priority dates in each category and for each country can change each month. However, please note that priority dates can also stay the same, they can move very slowly or progress by several months or years, and they can even move backward or retrogress. Therefore, there is no way to anticipate what the priority date will be in a future month or when a category will become current.