How to calculate the number of days between four date/time fields, excluding weekends

I have 4 date/time fields, I need to excluding weekends and Output fieldtype is Duration

Formula is WeekdaySub(ToDate([Completed Date]),ToDate([Start Date])) - WeekdaySub(ToDate([On Hold Stop Date]),ToDate([On Hold Start Date]))

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manohar vankireddy
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