Sample to send message via Pushover from Windows PowerShell

Send-Pushover.ps1

# Using any version of PowerShell
$parameters = New-Object System.Collections.Specialized.NameValueCollection
$parameters.Add("token", "APP_TOKEN")
$parameters.Add("user", "USER_KEY")
$parameters.Add("message", "hello world")
$client = New-Object System.Net.WebClient
$client.UploadValues("https://api.pushover.net/1/messages.json", $parameters)

# Using PowerShell v3 only with new Invoke-RestMethod cmdlet
$uri = 'https://api.pushover.net/1/messages.json'
$parameters = @{
    token = "APP_TOKEN"
    user = "USER_KEY"
    message = "hello world"
}
$parameters | Invoke-RestMethod -Uri $uri -Method Post

Can the current date, time and computer name be added to the body of the message using powershell?