function Get-NthDayOfWeekInMonth

function Get-NthDayOfWeekInMonth
    {
    <#
    .SYNOPSIS
        Short description

    .DESCRIPTION
        L-o-n-g
        d-e-s-c-r-i-p-t-i-o-n

    .PARAMETER NthDayNumber
        Which day instance you want. There are usually 4 of any given day, but sometimes there are 5.
        The default is 2.

    .PARAMETER DayOfWeek
        The day of the week to seek. This can be a day name OR a [System.DayOfWeek] object OR a number in 0..6 inclusive.
        The default is Tuesday.

    .PARAMETER MonthNumber
        The number of the month to work on.
        The default is the current month.

    .PARAMETER YearNumber
        The year number to work on.
        The default is the current year.

    .EXAMPLE
        Get-NthDayOfWeekInMonth

        Gets the 2nd Tuesday of the current month of the current year.

    .EXAMPLE
        Get-NthDayOfWeekInMonth -NthDayNumber 3 -DayOfWeek Monday

        Gets the 3rd Monday of the current year & month.

    .INPUTS
        Accepts [int32] for the *Number items, and a day name OR [DayOfWeek] enum value.
    .OUTPUTS
        Sends out a [DateTime] object.

    .NOTES
        Source  = the ISE snippets
        Version = 0.0.0.1
    #>

    [CmdletBinding ()]
    [Alias()]
    [OutputType([DateTime])]
    Param (
        # NthDayNumber help description goes here
        [Parameter (
            Position = 0,
            ValueFromPipeline,
            ValueFromPipelineByPropertyName
            )]
            [ValidateRange (1,5)]
            [int]
            $NthDayNumber = 2,

        # DayOfWeek help description goes here
        [Parameter (
            Position = 1,
            ValueFromPipelineByPropertyName
            )]
            [System.DayOfWeek]
            $DayOfWeek = [System.DayOfWeek]::Tuesday,

        # MonthNumber help description goes here
        [Parameter (
            Position = 2,
            ValueFromPipelineByPropertyName
            )]
            [ValidateRange (1,12)]
            [int]
            $MonthNumber = (Get-Date).Month,

        # YearNumber help description goes here
        [Parameter (
            Position = 3,
            ValueFromPipelineByPropertyName
            )]
            [ValidateRange (1950, 2199)]
            [int]
            $YearNumber = (Get-Date).Year
        )

    begin {}

    process
        {
        $FirstDayOfMonth = Get-Date -Year $YearNumber -Month $MonthNumber -Day 1

        # i have no idea what the logic behind the ofset number is
        #    i just fiddled with it until it came out right [*grin*]
        $Offset = (($DayOfWeek.value__ - $FirstDayOfMonth.DayOfWeek.value__ + 7) % 7) + (7 * ($NthDayNumber - 1))
        $TargetWeekDay = $FirstDayOfMonth.Date.AddDays($Offset)

        # correct for "5th weekday overflow"
        if ($TargetWeekDay.Month -ne $MonthNumber)
            {
            $TargetWeekDay = $TargetWeekDay.AddDays(-7)
            }

        $TargetWeekDay
        }

    end {}

    }