|Without a little more detail related to the layout of your sheet, it's hard for us to give you a direct answer. Please keep in mind that we can't see your spreadsheet from where we're sitting.|
What does this mean?
"I have a column for day as well as a selection for public holiday yes/no."
You might be able to use something like this, but this is nothing more than a guess:
Assume Column A contains your days and Column B contains Yes or No. Put this in C1 and drag it down:
=IF(OR(A1="Sunday",B1="Yes"),"Doubletime!","Time And A Half")
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