The NCLEX is administered (?) in the US by a company called PearsonVue.
You can visit their website at
There are no set dates, however; each applicant makes their own appointment once they have approval from the board of nursing in the state for which they are making application. Once you get authorization from the state, then you can check with PearsonVue to see what dates and times are available to schedule the exam. This can be done either on the telephone or online via the computer.
It's not like it used to be, with everyone taking the test(s) on certain dates or at certain times of the year. It's pretty much year-round now, with everything done on computer via the above-group.
Hope this helps -