It isn't currently possible to view collated figures for attendance figures split by the day of the week in Arbor. Please add any feedback around this topic, including how you'd like the data to be presented, to our Product Roadmap.
You can collect the data to analyse in Arbor but the collation and analysis of data will need to be done outside of Arbor. To collect this attendance data, you can use our Attendance Statistics page. This article shows how to use this page through Students > Attendance > Statistics.
You will need to change the dates day by day. For example, to collect Monday, you enter a Start and End date that fell on a Monday (e.g. 7th June 2021). This will give you a figure for Monday.
You can repeat this for each day of the week, and collate your results in an Excel file or Live Feed.
You'll likely find that collecting a sample size of 3-4 weeks would give you a general overview of what day has the lowest attendance. In this example, Monday is the day with the lowest attendance.