"Once a new variable hour, seasonal employee or part-time employee has been employed for an entire standard measurement period, the employee must be tested for full-time status, beginning with that standard measurement period, at the same time and under the same conditions as other ongoing employees.... [Here] is a simple visual sample of what your standard measurement periods might look like if you had a 1/1 renewal and selected 12-months. The vast majority of employers are electing to use 12-months to gain the longest period over which to average hours and to avoid having to repeat the ongoing calculation more than once a year."