You can use New-TimeSpan to define “amounts” of time, and then add or subtract them from dates. Here is an example:
$1Day = New-TimeSpan -Days 1 $today = Get-Date $yesterday = $today - $1Day $yesterday
A much easier way uses the built-in methods for DateTime objects:
$today = Get-Date $yesterday = $today.AddDays(-1) $yesterday
Also, you can use the TimeSpan .NET type to create time span objects:
PS C:\> [Timespan]::FromDays(1) Days : 1 Hours : 0 Minutes : 0 Seconds : 0 Milliseconds : 0 Ticks : 864000000000 TotalDays : 1 TotalHours : 24 TotalMinutes : 1440 TotalSeconds : 86400 TotalMilliseconds : 86400000
