Prof. Powershell

All The Time In The World

Stay on top of schedule with the New-TimeSpan cmdlet.

• By Jeffery Hicks
• 06/18/2008

The New-TimeSpan cmdlet creates a special type of object, called naturally, a TimeSpan. There a two ways to use this cmdlet. First, you can create a TimeSpan object of a specific length like this:

PS C:\> $timespan = new-timespan -days 1 -hour 1 -minute 30 -seconds 15
PS C:\> $timespan

Days : 1
Hours : 1
Minutes : 30
Seconds : 15
Milliseconds : 0
Ticks : 918150000000
TotalDays : 1.06267361111111
TotalHours : 25.5041666666667
TotalMinutes : 1530.25
TotalSeconds : 91815
TotalMilliseconds : 91815000

What I find useful is the automatically calculation for properties like total minutes:

PS C:\> $timespan.totalminutes
1530.25

Personally, I've always found the other New-Timespan syntax more valuable. Tell the cmdlet to create a timespan object calculated from a start date to an end date:

PS C:\> $ts=new-timespan (get-date) 6:00:00PM
PS C:\> write-host "You have $ts of work left to do."

You have -09:15:26.3770000 of work left to do.

The Timespan object is the difference between the current date and time and 6:00PM. All I've done is indicate how much longer the work day is. Depressing isn't it.

But here's one more way you might use this. Let's consider a folder of user files. The Get-ChildItem cmdlet will show you properties like when the file was created and when it as last modified. Wouldn't it be nice to get a simple value in days? Here's how:

dir c:\files | select FullName,CreationTime,@{name="CreationAge";
expression={[int](New-TimeSpan ($_.CreationTime) (Get-Date)).TotalDays }},
LastWriteTime,@{name="ModificationAge";
expression={[int](New-TimeSpan ($_.LastWriteTime) (Get-Date)).TotalDays }}

I use the Select-Object cmdlet to create a custom property like CreationAge. The value for this property is the TotalDays property of a time span object that is the difference between the object's CreationTime and the current date. I cast it as an integer to round the value:

expression={[int](New-TimeSpan ($_.CreationTime) (Get-Date)).TotalDays }}

When I run this expression, I get output like this for each file:

FullName : C:\files\users.txt
CreationTime : 11/9/2007 9:13:20 AM
CreationAge : 171
LastWriteTime : 1/2/2008 10:36:32 AM
ModificationAge : 117

FullName : C:\files\weather.xml
CreationTime : 11/21/2007 3:37:22 PM
CreationAge : 159
LastWriteTime : 1/17/2008 12:10:10 PM
ModificationAge : 102

I could even take this a step further and add this to the end of the expression:

| sort ModificationAge | export-csv c:\agereport.csv

This will sort the output by my custom ModificationAge property and send the results to a CSV.

The New-TimeSpan cmdlet won't extend your lunch break, but it might make some of your other administrative tasks a little less time-consuming.