Simple powershell Hijra date converter

I was recently looking for something to display Hijra calendar format in windows. If you have the system set up with specific locales then it should be an option to display on your system time. But if you want the gregorian date displayed as standard, but want to do quick Hijra date conversions, there is a .NET object to assist in that. System.Globalization.HijraCalendar assists with converting the dates, but of course the day value may not always be accurate, or agreed upon. I wanted to put together a simple powershell script for converting the current date, or any date provided to its appropriate day/month/year, including a text display of the name. So I have thrown together this very basic script for this:

#get-hijradate

if ($args[0] -eq $null) {
$mydt = [datetime]::Now
} else {
if ($args[0].gettype() -eq [datetime]) {
$mydt = $args[0]
} else {
$mydt = [datetime]::Now
}
}

$hjdt = New-Object System.Globalization.HijriCalendar

$hjday = $hjdt.getdayofmonth($mydt)
$hjmonth = $hjdt.getmonth($mydt)
$hjyear = $hjdt.getyear($mydt)
$hj_day_of_week = $hjdt.getdayofweek($mydt)

switch ($hjmonth) {
"1" {$hjmontxt = "Muharram"}
"2" {$hjmontxt = "Safar"}
"3" {$hjmontxt = "Rabi I"}
"4" {$hjmontxt = "Rabi II"}
"5" {$hjmontxt = "Jumada I"}
"6" {$hjmontxt = "Jumada II"}
"7" {$hjmontxt = "Rajab"}
"8" {$hjmontxt = "Shaban"}
"9" {$hjmontxt = "Ramadan"}
"10" {$hjmontxt = "Shawwal"}
"11" {$hjmontxt = "Zulkadah"}
"12" {$hjmontxt = "Zulhijjah"}
}
switch ($hj_day_of_week) {
"Monday" { $hjdaytxt = "Yawm al-Ithnayn"}
"Tuesday" { $hjdaytxt = "Yawm ath-Thalaathaa'"}
"Wednesday" { $hjdaytxt = "Yawm al-Arba'aa" }
"Thursday" { $hjdaytxt = "Yawm al-Khamīs"}
"Friday" {$hjdaytxt = "Yawm al-Jumu'ah"}
"Saturday" { $hjdaytxt = "Yawm as-Sabt"}
"Sunday" { $hjdaytxt = "Yawm al-Aḥad"}
}

$hjdisplay = [string]$hjday + " " + $hjmontxt + " " + [string]$hjyear
$result = New-Object PSObject
Add-Member -InputObject $result NoteProperty Day $hjday
Add-Member -InputObject $result NoteProperty Month $hjmonth
Add-Member -InputObject $result NoteProperty Year $hjyear
Add-Member -InputObject $result NoteProperty DayName $hjdaytxt
Add-Member -InputObject $result Noteproperty Display $hjdisplay
return $result

PS C:\> .\get-hijradate.ps1
Day Month     Year DayName             Display
--- -----     ---- -------             -------
16   10       1431 Yawm Al-Jumu'ah     14 Shawwal 1431