EDATE, EOMONTH, WORKDAY, NETWORKDAYS — Business Date Calculations with Spreadsheet Formulas in C#
"Due at the end of next month," "ship within 5 business days," "remind 3 business days before the deadline" — business apps are full of date rules that are surprisingly fiddly to hand-code with DateTime. Excel solved them long ago with EDATE, EOMONTH, WORKDAY, and NETWORKDAYS. This guide sorts out what each one does, the classic off-by-one traps, and how ReoGrid (supported in V4.5) runs the same formulas inside a WinForms / WPF app — no Office required.
