Similar to counties such as the UK and Netherlands, second level schools in Ireland are free to decide how to allocate instruction time between curriculum subjects. This results in variations between the quantum of time allocated to teaching mathematics in different schools and between different class groups within the same school. This quantitative study builds a profile for both lower second level (Junior Cycle) and upper second level (Senior Cycle) mathematics instruction time in Ireland. The results of the study highlight that although the proportion of time is on par with the OECD average, there are many issues of concern regarding instruction time in Ireland. These include the short length of the school year, experimentation with new teaching approaches, the high number of subjects studied, variations between individual school and class group allocations and the number of classes that do not take place.