FMLA Insights describes a 12-month rolling period as one that starts on a significant day of the year, such as an employee’s hire date, rather than on Jan. 1. A rolling 12-month period is often used to calculate an employee’s leave accrual and can be a different date for each employee in a company., Under the “rolling” method, known also in HR circles as the “look-back” method, the employer “looks back” over the last 12 months, adds up all the FMLA time the employee has used during the previous 12 months and subtracts that total from the employee’s 12-week leave allotment., A rolling 90-day period means that it only considers the last 90 days. So once something is 91 days old, it doesn't count., In the world of HR, a rolling year is a flexible 12 month period that starts with a specific event. This event might be an employee's first day of work, or the date they use their first day of leave. Unlike a calendar year, it doesn't reset on a fixed date but instead moves forward based on individual circumstances., Here are simple steps you can use to calculate FMLA leave using the rolling year method., .