Teachers in Singapore have criticised an international survey which found that they clock an average of 48 hours a week, saying they put in at least that amount.
The Straits Times spoke to 10 teachers, all of whom said the findings of the Organisation for Economic Cooperation and Development (OECD) - a Paris-based group of developed or developing countries - did not accurately reflect their typical day.
They said schooldays start as early as 6am and end 10 to 12 hours later - meaning at least 50 working hours a week.
Most of this time is spent teaching while the extra hours are filled with marking and necessary administrative work, including organising school activities.
Meanwhile, the Ministry of Education (MOE) said it has tried to ease their workload by hiring more teachers and support staff. Each primary and secondary school now has 14 more teachers on average than it did in 2004.
The Teaching and Learning International Survey, released on Wednesday, found teachers here spent almost twice the amount of time on marking and administrative work than their peers overseas. These duties take up nine and five hours respectively per week here, compared with global averages of five and three hours.
Teachers here cited large class sizes - 36 students compared with the global average of 24 - as a reason for this. Many also teach more than one class, meaning it takes longer to mark assignments, especially for essay-intensive and practice-heavy subjects such as languages, the humanities and maths.
One 30-year-old English and literature secondary school teacher said she spends eight hours marking scripts every week. She takes five classes, and mentors two groups of students on research.
The MOE told The Straits Times marking is "one way where teachers can find out whether individual students are learning".
Many teachers also give written feedback in addition to marks, which might explain the longer hours they spend, said its spokesman.
Teachers also said they are regularly tied up with administrative work, ranging from attendance records to planning trips to liaising with vendors for events.
A former secondary school art teacher quit in 2012 because she felt her weekly 60-hour work timetable, which included administrative work, was too gruelling.
"I had no time to invest in genuine lesson planning," she said.
A 27-year-old science teacher said days leading up to school events are packed with "ironing out details" and guiding student leaders in planning. He suggested having more support for logistical aspects such as food catering, as "it can be quite overwhelming for new teachers who need more time to plan lessons".
Like him, most teachers said such duties outside the classroom are "part and parcel of the job".
Another science teacher, who has taught for eight years, said: "Things like tracking students' grades and generating reports cannot be easily outsourced. Often, it's still work to give instructions to someone else to do the work."
The MOE said it will continue to support teachers so they can focus more on teaching.
Every school has an administrative team to assist in areas like finance, allied educators and school counsellors who provide emotional and learning support, its spokesman said.
However principals stressed that teaching is about caring for students in all aspects of school life.
Anglo-Chinese School (Barker Road) principal Peter Tan said: "Students may not remember the maths, science, geography after school. But they remember the interaction with teachers outside the classroom, in things like co-curricular activities. That's how teachers impart values."