Each time you certify effort, you do so for a specific period of performance. The periods of performance correspond to the fiscal year pay periods as they are earned.
For Faculty, PI's and Professional Unclassified staff the performance period will be semi-annual. All performance periods will reflect 13 pay periods (1-13 and 14-26).
For classified staff and students, the performance periods will be monthly. Most performance periods will reflect 2 pay periods, however, there will be 2 months a year that will have 3 pay periods.
The time during which you certify effort is called the certification window. Each certification window begins about a month after its corresponding period of performance.
Each time a semi-annual certification window begins, you have 21 days to certify the effort for the corresponding period of performance. Each time a monthly certification widow begins, you have 10 days to certify the corresponding period of performance.