hours worked when shifts involved

I have a Excel spreadsheet for work which logs sick hours and days. In my workplace different sections work different shifts e.g. 12 hours, 9.5 hours and the ususal 8 hours. Although I can calculate the days it isn't satisfactory because the days also includes non-work days. Different shifts for different sections also muck things up. Can anyone give me a template or guidance to work around the issue?