New-SprintCalendar.ps1

<#
.SYNOPSIS
Create an .ics file with a calendar of 28 sprints for a year. In each quarter, there are 6 sprints of 14 days each and 1 sprint of 7 days.
.PARAMETER Path
The path to the .ics file to create.
.PARAMETER StartDate
The start date of the first sprint.
.PARAMETER CalendarYear
The year of the calendar.
#>
param(
    [Parameter( Mandatory )]
    [ValidateScript({
        if ( $_.Split('.')[-1] -eq 'ics' ) { return $true }
        throw 'Destination path must be an .ics file'
    })]
    [string]
    $Path,
    [Parameter( Mandatory )]
    [datetime]
    $StartDate,
    [Parameter( Mandatory )]
    [string]
    $CalendarYear
)

$NowStamp = [datetime]::Now.ToUniversalTime().ToString('yyyyMMddTHHmmssZ')
$Cal = [System.Collections.Generic.List[string]]@(
    'BEGIN:VCALENDAR'
    'VERSION:2.0'
    'METHOD:PUBLISH'
    'PRODID:-//Braunweb//PowerShell ICS Creator Sample//EN'
)
foreach ( $Quarter in 1..4 ) {
    foreach ( $Sprint in 1..7 ) {
        $SprintLength = $Sprint -lt 7 ? 14 : 7
        $Cal.Add( 'BEGIN:VEVENT' )
        $Cal.Add( 'UID:{0}' -f [guid]::NewGuid() )
        $Cal.Add( 'CREATED:{0}' -f $NowStamp )
        $Cal.Add( 'DTSTAMP:{0}' -f $NowStamp )
        $Cal.Add( 'LAST-MODIFIED:{0}' -f $NowStamp )
        $Cal.Add( 'SEQUENCE:0' )
        $Cal.Add( 'DTSTART:{0}' -f $StartDate.ToString('yyyyMMdd') )
        $Cal.Add( 'DTEND:{0}' -f $StartDate.AddDays($SprintLength).ToString('yyyyMMdd') )
        #'RRULE:FREQ=YEARLY;INTERVAL=1'
        #'DESCRIPTION:{0}Q{1}-{2}' -f $StartDate.ToString('yy'), $Quarter, $Sprint
        $Cal.Add( ('SUMMARY:{0}Q{1}-{2}' -f $CalendarYear, $Quarter, $Sprint) )
        #'LOCATION:" + $eventLocatio'
        $Cal.Add( 'TRANSP:TRANSPARENT' )
        $Cal.Add( 'END:VEVENT' )
        $StartDate = $StartDate.AddDays($SprintLength)
    }
}
$Cal.Add( 'END:VCALENDAR' )

$Cal | Set-Content -Path $Path -Encoding UTF8