To mark period attendance, go to Attendance > Period Attendance then select Class, Section, Date and Subject and then click on Search button. The list of student will be shown in the below of the page.

Here select Attendance (Present, Late, Absent, Half day) for period/student and then click on Save Attendance button. Then select Mark as Holiday (National and Sunday holiday) and then click on the Save Attendance button.

Mark period attendance image

To edit period attendance, click on the Attendance (Present, Late, Absent, Half day) present in the student list.