At ZIS, students are expected to attend every day that the school is in session. Any absence (even because of ilness) will be considered unexcused unless the student/parent provides a medical report from the doctor. Attendance is taken at reading hour at 07.30 in the morning, and then the Vice Principal is informed of absentees. If a student arrives late at school, he/she must get a late slip from the Vice Principal to enter the class.

When a student misses more than TWENTY days of school in one academic year (excused  or unexcused by the school and without medical report), he/she maybe required to repeat the year as Ministry of Education of Cambodia requires.