Get-Quarter.ps1

#Define Quarters
$Quarters = @{}
$Start = Get-Date -Month 1 -Date 1 -Year (Get-Date).Year
ForEach ($Q in (1..4))
{
    $Quarters.Add($Q,[PSCustomObject]@{
        From = $Start
        To = $Start.AddMonths(3).AddTicks(-1)
    })
    $Start = $Start.AddMonths(3)
}

#Define this quarter
$Quarter = [int]([math]::Ceiling((Get-Date -Format MM)/3))