Show-Calendar, cal for PowerShell

This is a PowerShell implementation of the cal command found in Unix/Linux. Its task is quite simply to output a calendar view of the choosen month(s).

UPDATED 22.12.2014

I have made an update to the function. It now supports right-aligning the days in the output. In fact, Right alignment are now the default value. (Thanks Kirk!). I have also added support for using abbreviated names for days.

The biggest change however are the fact that the function is now culture-aware, and the default culture is the current culture. It supports specifying a specific culture, or you can use the Invariant Culture.

I have also decided to do something I thought I’d never do, I have used Format-Table for the output. This makes using Kirks FormatPx module even more desirable, as this is now the only way to get a proper PowerShell object out of this function.

The reason I made this change was that without FormatPx, the default output (list view) was not well suited for a calendar, and having to use Format-Table after the command each time, made it cumbersome to use.

A small note regarding the culture awareness: Since the days and the months are read from a CultureInfo object, they will display in the language of that culture. Since I use Week, Month and Year also as property names, and since these will still be visible in English, I have added a translation hash table to the script. I have added translations for a handful of different languages already, but if yours is missing, and you would like it added, please let me know, and I’ll add it to the code!


Original post text

You can choose the starting month and year, and how many months to show, as well as parameters to mark day(s) as well as a specific date. The current date will also be marked in the calendar.

Since this is PowerShell the days are of course datetime objects and not just text, but because of this the default output formatting is not ideal for a calendar view. I have built-in support for the excellent FormatPx module by Kirk Munro, so if you are using this module the output will look like this:

cal001

If you don’t have FormatPx and don’t want to use it, I suggest using Format-Table to get the calendar view somewhat readable on the screen. The following image shows how that will look:

cal002

But seriously, if you haven’t checked out FormatPx yet, head on over to Kirks github project and give it a try!

And now for some code:

function Show-Calendar {
<#
.SYNOPSIS
Show calendar.
.DESCRIPTION
This function is a PowerShell version of the *NIX cal command and will show a
calendar of the chosen month(s). The current day will be marked with a '*'.
For best results, use together with the FormatPx module by Kirk Munro.
.EXAMPLE
Show-Calendar
Will show a calendar view of the current month.
.EXAMPLE
Show-Calendar -InvariantCulture
Will show a calendar view of the current month, using the Invariant Culture
.EXAMPLE
Show-Calendar -Culture 'de-DE'
Will show a calendar view of the current month, using the de-DE (German) culture.
.EXAMPLE
Show-Calendar 1 2015 -m 3
Will show a calendar view of the first three months in 2015.
.EXAMPLE
Show-Calendar 12 -MarkDay 25 -Abbreviated
Will show a calendar view of december and mark December 25, with abbreviated day names.
.EXAMPLE
Show-Calendar 1 2015 -m 12 -MarkDate (Get-Date -Year 2015 -Month 2 -Day 14)
Will show a calendar view of 2015 and mark 14th of February.
.LINK
https://github.com/KirkMunro/FormatPx
.NOTES
Author: Øyvind Kallstad
Date: 21.12.2014
Version: 1.1
22.12.2014
Added Alignment parameter
Made the entire function culture aware
Added support for abbreviated day names
#>
[CmdletBinding(DefaultParameterSetName = 'Culture')]
param (
# The starting month number. Default is current month.
[Parameter(Position = 0)]
[Alias('Month')]
[ValidateRange(1,12)]
[int] $StartMonth = [DateTime]::Now.Month,
# The starting year. Default is current year.
[Parameter(Position = 1)]
[Alias('Year')]
[ValidateRange(1,9999)]
[int32] $StartYear = [DateTime]::Now.Year,
# How many months to show. Default is 1.
[Parameter()]
[Alias('m')]
[ValidateRange(1,[int]::MaxValue)]
[int32] $Months = 1,
# Day to mark on the calendar.
[Parameter()]
[ValidateRange(1,31)]
[int32] $MarkDay,
# Date to mark on the calendar.
[Parameter()]
[datetime] $MarkDate,
# Set alignment of the dates in the output. Default value is 'Right'.
[Parameter()]
[ValidateSet('Left','Right')]
[string] $Alignment = 'Right',
# Use the Invariant Culture (English).
[Parameter(ParameterSetName = 'InvariantCulture')]
[switch] $InvariantCulture,
# Use this parameter to choose what culture to use. If this parameter is not used and
# the InvariantCulture parameter is false, the current culture will be used instead.
[Parameter(ParameterSetName = 'Culture')]
[string] $Culture,
# Use this parameter to use abbreviated day names. Default is to use the full name of days.
[Parameter()]
[switch] $AbbreviatedDayNames
)
function New-DayOfWeekString {
<#
.SYNPSIS
Output a culture aware string of a specified week day.
.NOTES
Author: Øyvind Kallstad
#>
[CmdletBinding()]
[OutputType([String])]
param (
# The day of week in Invariant Culture (English).
[Parameter(Position = 0, Mandatory)]
[System.DayOfWeek] $DayOfWeek,
[Parameter(Position = 1, ValueFromPipeline)]
[CultureInfo] $CultureInfo = [System.Globalization.CultureInfo]::CurrentCulture,
# Show the week day in an abbreviated form.
[Parameter()]
[switch] $Abbreviated
)
if ($Abbreviated) {
Write-Output ($cultureInfo.TextInfo.ToTitleCase($cultureInfo.DateTimeFormat.GetAbbreviatedDayName([System.DayOfWeek]::$DayOfWeek)))
}
else {
Write-Output ($cultureInfo.TextInfo.ToTitleCase($cultureInfo.DateTimeFormat.GetDayName([System.DayOfWeek]::$DayOfWeek)))
}
}
function New-Week {
<#
.SYNOPSIS
Returns an ordered dictionary representing a week.
.NOTES
Author: Øyvind Kallstad
#>
[CmdletBinding()]
[OutputType([System.Collections.Specialized.OrderedDictionary])]
param (
[Parameter(Position = 0, ValueFromPipeline)]
[CultureInfo] $CultureInfo = [System.Globalization.CultureInfo]::CurrentCulture,
# Show the week day in an abbreviated form.
[Parameter()]
[switch] $Abbreviated
)
$propHash = @{
CultureInfo = $CultureInfo
}
if ($Abbreviated) {
$propHash.Abbreviated = $true
}
# define week day names
$monday = New-DayOfWeekString 'Monday' @propHash
$tuesday = New-DayOfWeekString 'Tuesday' @propHash
$wednesday = New-DayOfWeekString 'Wednesday' @propHash
$thursday = New-DayOfWeekString 'Thursday' @propHash
$friday = New-DayOfWeekString 'Friday' @propHash
$saturday = New-DayOfWeekString 'Saturday' @propHash
$sunday = New-DayOfWeekString 'Sunday' @propHash
$week = [Ordered] @{
$tuesday = $null
$wednesday = $null
$thursday = $null
$friday = $null
$saturday = $null
}
if (($CultureInfo.DateTimeFormat.FirstDayOfWeek) -eq 'Monday') {
$week.Insert(0, $monday, $null)
$week.Add($sunday, $null)
}
else {
$week.Insert(0, $sunday, $null)
$week.Insert(1, $monday, $null)
}
Write-Output $week
}
# get a CultureInfo object based on user input
# either with an Invariant Culture…
if ($InvariantCulture) {
$cultureInfo = [System.Globalization.CultureInfo]::InvariantCulture
}
# … user defined culture…
elseif ($Culture) {
$cultureInfo = [System.Globalization.CultureInfo]::CreateSpecificCulture($Culture)
}
# … or the current culture
else {
$cultureInfo = [System.Globalization.CultureInfo]::CurrentCulture
}
# supporting internationalization
# add additional languages as needed
switch ($cultureInfo.Name) {
'nb-NO' {$translate = @{Year = 'År'; Month = 'Måned'; Week = 'Uke'}} # Norwegian (Bokmål)
'da-DK' {$translate = @{Year = 'År'; Month = 'Måned'; Week = 'Uge'}} # Danish
'sv-SE' {$translate = @{Year = 'År'; Month = 'Månad'; Week = 'Vecka'}} # Swedish
'fi-FI' {$translate = @{Year = 'Vuosi'; Month = 'Kuukausi'; Week = 'Viikko'}} # Finnish
'de-DE' {$translate = @{Year = 'Jahr'; Month = 'Monat'; Week = 'Woche'}} # German
'de-AT' {$translate = @{Year = 'Jahr'; Month = 'Monat'; Week = 'Woche'}} # German (Austria)
'de-CH' {$translate = @{Year = 'Jahr'; Month = 'Monat'; Week = 'Woche'}} # German (Switzerland)
'nl-NL' {$translate = @{Year = 'Jaar'; Month = 'Maand'; Week = 'Week'}} # Dutch
'fr-FR' {$translate = @{Year = 'Année'; Month = 'Mois'; Week = 'Semaine'}} # French
'fr-CH' {$translate = @{Year = 'Année'; Month = 'Mois'; Week = 'Semaine'}} # French (Switzerland)
'fr-LU' {$translate = @{Year = 'Année'; Month = 'Mois'; Week = 'Semaine'}} # French (Luxembourg)
'it-IT' {$translate = @{Year = 'Anno'; Month = 'Mese'; Week = 'Settimana'}} # Italian
'es-ES' {$translate = @{Year = 'Año'; Month = 'Mes'; Week = 'Semana'}} # Spanish
'ru-RU' {$translate = @{Year = 'Год'; Month = 'Месяц'; Week = 'Неделя'}} # Russian
'cs-CZ' {$translate = @{Year = 'Rok'; Month = 'Měsíc'; Week = 'Týden'}} # Czech
'ms-MY' {$translate = @{Year = 'Tahun'; Month = 'Bulan'; Week = 'Minggu'}} # Malay
'ja-JP' {$translate = @{Year = ''; Month = ''; Week = '1週間'}} # Japanese
'is-IS' {$translate = @{Year = 'Ári'; Month = 'Mánuði'; Week = 'Viku'}} # Icelandic
'pl-PL' {$translate = @{Year = 'Rok'; Month = 'Miesiąc'; Week = 'Tydzień'}} # Polish
'cy-GB' {$translate = @{Year = 'Blwyddyn'; Month = 'Mis'; Week = 'Wythnos'}} # Welsh (United Kingdom)
DEFAULT {$translate = @{Year = 'Year'; Month = 'Month'; Week = 'Week'}} # Invariant Culture (English)
}
$thisMonth = $StartMonth 1
$thisYear = $StartYear
$output = @()
$weekProperties = @{}
if ($AbbreviatedDayNames) { $weekProperties.Abbreviated = $true }
# loop through the months
for ($i = 1; $i -le $Months; $i++) {
# increment month
$thisMonth++
# when month is greater than 12, a new year is triggered, so reset month to 1 and increment year
if ($thisMonth -gt 12) {
$thisMonth = 1
$thisYear++
}
# get the number of days in the month
$daysInMonth = $cultureInfo.Calendar.GetDaysInMonth($thisYear,$thisMonth)
# define new week
$thisWeek = $cultureInfo | New-Week @weekProperties
$thisWeek.Insert(0, $translate.Month, $null)
$thisWeek.Insert(1, $translate.Year, $null)
$thisWeek.Insert(2, $translate.Week, $null)
# loop through each day in the month
for ($y = 1; $y -lt ($daysInMonth + 1); $y++) {
# get a datetime object of the current date
$thisDate = New-Object TypeName 'System.DateTime' ArgumentList ($thisYear,$thisMonth,$y,$cultureInfo.Calendar)
# if current date is the first day of a week (but not if it's the very first day of the month at the same time)
if (($thisDate.DayOfWeek -eq ($cultureInfo.DateTimeFormat.FirstDayOfWeek)) -and ($y -gt 1)) {
# add the week object to the output array
$weekObject = New-Object TypeName 'PSCustomObject' Property $thisWeek
$output += $weekObject
# reset the week
$thisWeek = $cultureInfo | New-Week @weekProperties
$thisWeek.Insert(0, $translate.Month, $null)
$thisWeek.Insert(1, $translate.Year, $null)
$thisWeek.Insert(2, $translate.Week, $null)
}
# get string representation of the month and the current week number (if week number is 53, change to 1)
$monthString = $cultureInfo.TextInfo.ToTitleCase($thisDate.ToString('MMMM',$cultureInfo))
$thisWeekNumber = $cultureInfo.calendar.GetWeekOfYear($thisDate,$cultureInfo.DateTimeFormat.CalendarWeekRule,$cultureInfo.DateTimeFormat.FirstDayOfWeek)
if ($thisWeekNumber -eq 53) { $thisWeekNumber = 1 }
# overload the ToString method of the datetime object
$thisDate | Add-Member MemberType ScriptMethod Name 'ToString' Value {
# mark today with '*'
if (($this.Date) -eq ([DateTime]::Now.Date)) {
if($Alignment -eq 'Left') {$this.Day.ToString() + '*'}
else {'*' + $this.Day.ToString()}
}
elseif ($MarkDay -eq $this.Day) {
if($Alignment -eq 'Left') {$this.Day.ToString() + '!'}
else {'!' + $this.Day.ToString()}
}
elseif ($MarkDate.Date -eq $this.Date) {
if($Alignment -eq 'Left') {$this.Day.ToString() + '!'}
else {'!' + $this.Day.ToString()}
}
else {
$this.Day.ToString()
}
} Force
# update the week hashtable with the current day, week, month and year
$thisWeek[($cultureInfo | New-DayOfWeekString ($thisDate.DayOfWeek) Abbreviated:$AbbreviatedDayNames)] = $thisDate
$thisWeek[$translate.Week] = $thisWeekNumber
$thisWeek[$translate.Month] = $monthString
$thisWeek[$translate.Year] = $thisYear
}
# add the final week to the output array
$weekObject = New-Object TypeName 'PSCustomObject' Property $thisWeek
$output += $weekObject
}
# translate day names
$monday = $cultureInfo | New-DayOfWeekString 'Monday' Abbreviated:$AbbreviatedDayNames
$tuesday = $cultureInfo | New-DayOfWeekString 'Tuesday' Abbreviated:$AbbreviatedDayNames
$wednesday = $cultureInfo | New-DayOfWeekString 'Wednesday' Abbreviated:$AbbreviatedDayNames
$thursday = $cultureInfo | New-DayOfWeekString 'Thursday' Abbreviated:$AbbreviatedDayNames
$friday = $cultureInfo | New-DayOfWeekString 'Friday' Abbreviated:$AbbreviatedDayNames
$saturday = $cultureInfo | New-DayOfWeekString 'Saturday' Abbreviated:$AbbreviatedDayNames
$sunday = $cultureInfo | New-DayOfWeekString 'Sunday' Abbreviated:$AbbreviatedDayNames
# define a hashtable to hold format properties for the table output
if (($cultureInfo.DateTimeFormat.FirstDayOfWeek) -eq 'Monday') {
$formatProperties = @{
Property =
"$($translate.Week)",
@{Name = "$monday" ;Expression = {$_.$monday} ;Alignment = $Alignment},
@{Name = "$tuesday" ;Expression = {$_.$tuesday} ;Alignment = $Alignment},
@{Name = "$wednesday" ;Expression = {$_.$wednesday} ;Alignment = $Alignment},
@{Name = "$thursday" ;Expression = {$_.$thursday} ;Alignment = $Alignment},
@{Name = "$friday" ;Expression = {$_.$friday} ;Alignment = $Alignment},
@{Name = "$saturday" ;Expression = {$_.$saturday} ;Alignment = $Alignment},
@{Name = "$sunday" ;Expression = {$_.$sunday} ;Alignment = $Alignment}
}
}
else {
$formatProperties = @{
Property =
"$($translate.Week)",
@{Name = "$sunday" ;Expression = {$_.$sunday} ;Alignment = $Alignment},
@{Name = "$monday" ;Expression = {$_.$monday} ;Alignment = $Alignment},
@{Name = "$tuesday" ;Expression = {$_.$tuesday} ;Alignment = $Alignment},
@{Name = "$wednesday" ;Expression = {$_.$wednesday} ;Alignment = $Alignment},
@{Name = "$thursday" ;Expression = {$_.$thursday} ;Alignment = $Alignment},
@{Name = "$friday" ;Expression = {$_.$friday} ;Alignment = $Alignment},
@{Name = "$saturday" ;Expression = {$_.$saturday} ;Alignment = $Alignment}
}
}
# if FormatPx is loaded, use it to format the output
if (Get-Module Name 'FormatPx') {
Write-Output ($output | Format-Table @formatProperties AutoSize GroupBy @{Name = "$($translate.Month)";Expression = {"$($_.($translate.Month)) $($_.($translate.Year))"}} PersistWhenOutput)
}
# else use default PowerShell formatting
else {
Write-Output ($output | Format-Table @formatProperties AutoSize GroupBy @{Name = "$($translate.Month)";Expression = {"$($_.($translate.Month)) $($_.($translate.Year))"}})
}
}
New-Alias Name 'cal' Value 'Show-Calendar' Force

view raw
Show-Calendar.ps1
hosted with ❤ by GitHub

3 comments

    1. Thanks Jeffrey. Interesting to see how differently we have approached the same goal. The good thing about your code is that since you are not actually outputting the words ‘Week’, ‘Month’ and ‘Year’ as I do, you are not getting into the trouble of these being in a different language than the name of the days. Speaking of culture.. it was a lot more work than I thought it would be to get it totally culture/language aware, but I’m quite satisfied with the result. Hopefully there are not too many nasty bugs in there! 🙂

      Like

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