Function: Get Maintenance Window Status (VBScript, ASP and PowerShell flavors)

A little function you can use to determine if a date/time window is active, pending or expired.  I've provided both PowerShell, VBScript and ASP examples (almost the same thing).

Note that PowerShell requires defining the function before invoking it, with regards to single-file, sequential ("top-down") processing order.

[powershell]
function Get-TimeWindowStatus {
    Param(
        [parameter(Mandatory=$true)]$Start,
        [parameter(Mandatory=$true)]$End
    )
    $now = Get-Date
    $dif1 = $(New-TimeSpan -Start $Start -End $now).Minutes
    $dif2 = $(New-TimeSpan -Start $End -End $now).Minutes
    if ($dif1 -lt 0) {
        return -1
    }
    elseif ($dif2 -gt 0) {
        return 1
    }
    else {
        return 0
    }
}

$d1 = "8/27/2014 9:30:00"
$d2 = "8/27/2014 10:00:00"

switch (Get-TimeWindowStatus -Start $d1 -End $d2) {
    -1 {write-host "Maintenance window has not begun."}
    1  {write-hsot "Maintenance window has expired."}
    default {Write-Host "Maintenance window is active."}
}
[/powershell]

ASP and VBScript on the other hand pre-process script code, so you can define functions anywhere within a given script file, and the location for invoking the function doesn't matter as long as it's in the same file (or loaded in advance using "#include" if using ASP).

[asp]
d1 = "8/26/2014 16:00"
d2 = "8/27/2014 9:00"

Select Case TIME_WINDOW_STATUS (d1, d2)
    Case 0:  Response.Write "Maintenance window is in effect."
    Case 1:  Response.Write "Maintenance window has expired."
    Case -1: Response.Write "Maintenance window has not begun."
End Select

Function TIME_WINDOW_STATUS (startDT, endDT)
    Dim dd1, dd2, result
    dd1 = DateDiff("n", d1, NOW)
    dd2 = DateDiff("n", d2, NOW)
    If dd1 > 0 And dd2 < 0 Then 
        result = 0
    ElseIf dd1 < 0 Then
        result = -1
    ElseIf dd2 > 0 Then
        result = 1
    End If
    TIME_WINDOW_STATUS = result
    End Function

[/asp]

[vbscript]
d1 = "8/26/2014 16:00"
d2 = "8/27/2014 9:00"

Select Case TIME_WINDOW_STATUS (d1, d2)
    Case 0:  wscript.echo "Maintenance window is in effect."
    Case 1:  wscript.echo "Maintenance window has expired."
    Case -1: wscript.echo "Maintenance window has not begun."
End Select

Function TIME_WINDOW_STATUS (startDT, endDT)
    Dim dd1, dd2, result
    dd1 = DateDiff("n", d1, NOW)
    dd2 = DateDiff("n", d2, NOW)
    If dd1 > 0 And dd2 < 0 Then 
        result = True
    ElseIf dd1 < 0 Then
        result = False
    ElseIf dd2 > 0 Then
        result = False
    End If
    TIME_WINDOW_STATUS = result
End Function

[/vbscript]