Imports System

imports System.Collections.Generic

imports System.Linq

Public Module Module1

    Public Sub Main()

        For i As Int32 = 1 To 12

            Dim fridays = GetWeekDaysInMonth(2022, i, DayOfWeek.Friday)

            Console.WriteLine(String.Join(", ", fridays.Select(Function(d) d.ToShortDateString())))

        Next

    End Sub

    Public Iterator Function GetWeekDaysInMonth(year As Int32, month As Int32, dayOfWeek As DayOfWeek) As IEnumerable(Of Date)

        Dim day = New Date(year, month, 1)

        Dim diff As Int32 = (7 + (day.DayOfWeek - dayOfWeek)) Mod 7

        day = day.AddDays(-1 * diff)

        If day.Month <> month Then day = day.AddDays(7)

        While day.Month = month

            Yield day

            day = day.AddDays(7)

        End While

    End Function

End Module