Get-Calendar.ps1

function Get-Calendar {
    <# 
    .SYNOPSIS 
        Prints a calendar for the provided month and year
    .DESCRIPTION 
        Provided with a month number and a year, prints a month calendar with week starting on monday.
    .NOTES 
        Author     : Tormod Fjeldskår 
    .EXAMPLE 
        C:\PS> Get-Calendar 2 2016
        Prints the calendar for February 2016
    .PARAMETER month 
       The number of the month to print.
    .PARAMETER year 
       The year of the month to print.
    #> 

    param (
        [Parameter(Mandatory=$true)]
        [int]$month,
        [Parameter(Mandatory=$true)]
        [int]$year
    )


    $date = Get-Date -Day 1 -Month $month -Year $year

    ## Print month name and year as heading
    $heading = $date.ToString("MMMM yyyy", [System.Globalization.CultureInfo]::InvariantCulture)
    $headingPadding = (20 - $heading.Length) / 2
    
    Write-Host ""
    Write-Host "".PadLeft($headingPadding) -NoNewline
    Write-Host $heading -ForegroundColor Yellow

    Write-Host "Mo Tu We Th Fr Sa Su" -ForegroundColor Gray

    ## Pad first week with spaces if necessary
    $firstWeekDayNumber = ($date.DayOfWeek + 6) % 7 # Because normal people consider Monday first day of week
    $firstWeekDayPadding = $firstWeekDayNumber * 3

    Write-Host "".PadLeft($firstWeekDayPadding) -NoNewline
 
    ## Print days as long as month is the same   
    while($date.Month -eq $month) {
        if($date.DayOfWeek -eq [System.DayOfWeek]::Sunday) {
            Write-Host ("" + $date.Day).PadLeft(2) -ForegroundColor Red
        }
        else {
            Write-Host ("" + $date.Day).PadLeft(2).PadRight(3) -NoNewline
        }
        $date = $date.AddDays(1)
    }

    ## Provide whitespace before next command
    Write-Host ""
    Write-Host ""
}
Set-Alias cal Get-Calendar