How to format a DateTime in PowerShell

Question

I can format the Get-Date cmdlet no problem like this:

$date = Get-Date -format "yyyyMMdd"

But once I've got a date in a variable, how do I format it? The statement below

$dateStr = $date -format "yyyMMdd"

returns this error:

"You must provide a value expression on the right-hand side of the '-f' operator"

I actually wished this syntax worked. `$date -format "yyyMMdd"` is much more intuitive for formatting a single object than `'{0:yyyyMMdd}' -f $date`. — orad, Jul 28 '15 at 23:51
As an aside: PowerShell has an `-f` operator (with the syntax as shown in the accepted answer), but no `-format` operator. The error message is complaining about `ormat` not being a valid RHS operand, but note that recent PowerShell versions actually emit a different, more helpful error message: `Unexpected token '-format' in expression or statement` — mklement0, Jan 22 '20 at 19:08
@orad your comment does vastly more to explain the "{0:...}" syntax boilerplate than the top+accepted answer that suggests it. Thank you. (Your comment tells us that it's a special case of something that supports multiple things being formatted at once, which in turn lets us realize that we're looking at something far more general than just syntactic sugar for `.ToString(...)`... and that, combined with enough programming experience, we can guess that the format strings use zero-indexed references to the objects being interpolated, and use {} to wrap placeholders.) — mtraceur, Oct 06 '22 at 05:47

score 304 · Accepted Answer · edited Jan 14 '19 at 06:07

304

The same as you would in .NET:

$DateStr = $Date.ToString("yyyyMMdd")

Or:

$DateStr = '{0:yyyyMMdd}' -f $Date

edited Jan 14 '19 at 06:07

Peter Mortensen

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answered Feb 12 '10 at 04:16

Josh

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Results in: `You cannot call a method on a null-valued expression.` – Langdon Jun 03 '21 at 11:28
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@Langdon - Assuming you are using the form $Date.ToString(...) then that error is because your $Date variable contains Null. You'll need to make sure you've actually assigned a DateTime value to it before calling ToString. ... The second form (using the -f operator) appears to tolerate nulls and will simply output an empty string. – Daniel Scott Aug 08 '21 at 02:21
I want to +1 but the totally cryptic appearance of "0:" and wrapping "{...}" with no explanation is really offputting for me. Why are they there? what are they saying to PowerShell or to the "-f" operator or to [...]? – mtraceur Oct 06 '22 at 05:42

Stephen · Answer 2 · 2022-10-31T21:22:35.373

46

A simple and nice way is:

$time = (Get-Date).ToString("yyyy:MM:dd")

edited Oct 31 '22 at 21:22

answered Aug 19 '16 at 19:34

Stephen

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This was the only approach that didn't throw a null-valued expression error for me. Thanks. – Cwista Jul 05 '18 at 13:15
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Ummm, doesn't this return the date formatted as a 24-hour time or am I being too US-Centric??? – Allen Dec 30 '20 at 16:51
It’s in any format you specify. Regardless of your place of origin. – Stephen Dec 30 '20 at 17:14
This is a better answer as the others had issues for me – Mike Q Mar 12 '21 at 18:11

score 34 · Answer 3 · edited Jun 15 '20 at 22:34

34

The question is answered, but there is some more information missing:

Variable vs. Cmdlet

You have a value in the $Date variable and the -f operator does work in this form: 'format string' -f values. If you call Get-Date -format "yyyyMMdd" you call a cmdlet with some parameters. The value "yyyyMMdd" is the value for parameter Format (try help Get-Date -param Format).

-f operator

There are plenty of format strings. Look at least at part1 and part2. She uses string.Format('format string', values'). Think of it as 'format-string' -f values, because the -f operator works very similarly as string.Format method (although there are some differences (for more information look at question at Stack Overflow: How exactly does the RHS of PowerShell's -f operator work?).

edited Jun 15 '20 at 22:34

DixonD

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answered Feb 12 '10 at 05:31

stej

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What he is saying is that the -Format parameter causes Get-DateTime to return a string, not a DateTime object. So your variable $Date can no longer be formatted as expected. I REALLY wish the the -Format parameter would simply change the default behavior of a particular DateTime object's ToString method. Then it would work as you had expected. – Nathan Hartley Feb 02 '12 at 16:01
Either put examples in or append your comments to the selected answer. IMO – Mike Q Sep 29 '21 at 13:05

score 28 · Answer 4 · edited Jan 14 '19 at 06:15

28

A very convenient -- but probably not all too efficient -- solution is to use the member function GetDateTimeFormats(),

$d = Get-Date
$d.GetDateTimeFormats()

This outputs a large string-array of formatting styles for the date-value. You can then pick one of the elements of the array via the []-operator, e.g.,

PS C:\> $d.GetDateTimeFormats()[12]
Dienstag, 29. November 2016 19.14

edited Jan 14 '19 at 06:15

Peter Mortensen

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answered Nov 29 '16 at 18:19

davidhigh

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I like this answer because it encourages us to explore possibilities. – Joshua K Aug 31 '22 at 21:53

score 23 · Answer 5 · edited Mar 29 '17 at 19:14

23

One thing you could do is:

$date.ToString("yyyyMMdd")

edited Mar 29 '17 at 19:14

davidhigh

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answered Feb 12 '10 at 04:15

John Weldon

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Thanks I did this - bugs me that -format doesn't work though. – Ev. Feb 12 '10 at 04:20

score 12 · Answer 6 · edited Jan 22 '20 at 19:11

12

Do this if you absolutely need to use the -Format option:

$dateStr = Get-Date $date -Format "yyyMMdd"

However

$dateStr = $date.toString('yyyMMdd')

is probably more efficient.. :)

edited Jan 22 '20 at 19:11

mklement0

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answered May 23 '17 at 11:11

tplive

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`$dateStr = (Get-Date $date -Format "yyyMMdd")` results in an object type that is different from a datetime object. Try playing around with this `$dateStr = [datetime](Get-Date $date -Format "yyyMMdd")` You'll see the difference right away. – Jamie Marshall Sep 07 '17 at 20:03
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Well, yeah.. It's a String, that's why I named it dateStr.. :) OP was trying to format a date object to a String. – tplive Sep 10 '17 at 10:05

score 6 · Answer 7 · edited Jan 22 '20 at 19:12

6

If you got here to use this in cmd.exe (in a batch file):

powershell -Command (Get-Date).ToString('yyyy-MM-dd')

edited Jan 22 '20 at 19:12

mklement0

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answered May 17 '17 at 10:13

Jaroslav Záruba

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score 6 · Answer 8 · answered May 16 '19 at 18:30

6

For anyone trying to format the current date for use in an HTTP header use the "r" format (short for RFC1123) but beware the caveat...

PS C:\Users\Me> (get-date).toString("r")
Thu, 16 May 2019 09:20:13 GMT
PS C:\Users\Me> get-date -format r
Thu, 16 May 2019 09:21:01 GMT
PS C:\Users\Me> (get-date).ToUniversalTime().toString("r")
Thu, 16 May 2019 16:21:37 GMT

I.e. Don't forget to use "ToUniversalTime()"

answered May 16 '19 at 18:30

Peter L

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Use this with "o" for "xml" style datetimes – JohnOpincar Jun 03 '19 at 21:04

score 5 · Answer 9 · answered Aug 17 '18 at 15:39

Very informative answer from @stej, but here is a short answer: Among other options, you have 3 simple options to format [System.DateTime] stored in a variable:

Pass the variable to the Get-Date cmdlet: Get-Date -Format "HH:mm" $date
Use toString() method: $date.ToString("HH:mm")
Use Composite formatting: "{0:HH:mm}" -f $date

score 5 · Answer 10 · 2020-01-22T19:18:43.523

5

I needed the time and a slight variation on format. This works great for my purposes:

$((get-date).ToLocalTime()).ToString("yyyy-MM-dd HHmmss")

2019-08-16 215757

According to @mklement0 in comments, this should yield the same result:

(get-date).ToString("yyyy-MM-dd HHmmss")

edited Jan 22 '20 at 19:18

answered Aug 16 '19 at 14:59

score 2 · Answer 11 · answered Jul 03 '21 at 16:44

Format Date Time to your Output Needs

If you want to format the date and assign the string to a variable. I have combined both PowerShell and .NET to provide the flexibility.

    $oDate = '{0}' -f ([system.string]::format('{0:yyyyMMddHHmmss}',(Get-Date)))

How this Works

PowerShell Operator - '{0}' -f (.....)
.NET Notation - [system.string]::format('customformat',InputObject)
Customised Format by combining PowerShell with .NET - '{0:yyyyMMddHHmmss}'
Input Object provided by PowerShell cmdlet - (Get-Date)
Stored in the PowerShell variable - $oDate

Example

If the date and time when run was Monday, 5 July 2021 5:45:22 PM (Format '{0:F}').

$oDate = 20210705174522

Using the Code

You can customise the the string to meet your requirements by modifying 'yyyMMddHHmmss' using the Microsoft .NET Custom Date Time Notation.

why not just? [string]$oDate = '([system.string]::format('{0:yyyyMMddHHmmss}',(Get-Date))) — ChrisN, Feb 22 '22 at 17:15

Phil Pritchett · Answer 12 · 2021-05-28T19:03:36.723

You could just use this to select the format you want and then past it wherever it is needed.

$DTFormats = (Get-Date).GetDateTimeFormats()
$Formats = @()
$i=0
While ($i -lt $DTFormats.Count){
    $row = [PSCustomObject]@{
        'IndexNumber' = $i
        'DateTime Format' = $DTFormats[$i]
    }
    $Formats += $row
    $i++
}

$DTSelection = ($Formats | Out-GridView -OutputMode Single -Title 'Select DateTime Format').IndexNumber
$MyDTFormat = "(Get-Date).GetDateTimeFormats()[$DTSelection]"
Write-Host " "
Write-Host " Use the following code snippet to get the DateTime format you selected:"
Write-Host "    $MyDTFormat" -ForegroundColor Green
Write-Host " "
$MyDTFormat | Clip
Write-Host " The code snippet has been copied to your clipboard. Paste snippet where needed."

score 0 · Answer 13 · answered Sep 09 '22 at 21:20

0

I converted my dueDate string to a datetime then formatted it.

 [Datetime]::ParseExact($dueDate,'MM/dd/yyyy H:mm:ss',$null).ToString('MM/dd/yyyy')

answered Sep 09 '22 at 21:20

Golden Lion

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How to format a DateTime in PowerShell

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