How can i add column to existing data table to get Ageing days


I am new to UiPath and programming. Can someone help me in addressing the below query:

How can i add column to existing data table validating with Date column. As per below

DemandID RequiredBy DemandStatus Ageing

123456| 25 Dec 2018 Not Done I need days difference from B col(RequiredBy to Date.Now
654321 01 Feb 2019 Done
231654 01 Feb 2019 Done
564321 01 Feb 2019 Done
102020 01 Feb 2019 Done
123333 02 Jan 2019 Not Done

Hi @mohammed.khan39

Have you tried using the activity add data columns

Thanks for the prompt response.

I tried adding data column activity. After that I have to give expression to fetch the ageing difference from today. I dont know which activity to use further


Let us take you are having a dataTable dta
Now Add Column Ageing to dta by using Add Data Column Activity.

Now run For Each row for dta

Now Inside ForEach, Use One Assign Activity.
row(“Ageing”)=(DateTime.Now-DateTime.ParseExact(row(“RequiredBy”).Tostring,“dd MMM yyyy”,System.Globalization.CultureInfo.InvarientCulture)).Days.ToString


1 Like

Thank you mahesh, However I am getting error when i use assign activity…

pls let me know is it work for u or not
u has to use todays date as i have send my project wf image

This error is because the spelling of Invariant is wrong as @MAHESH1 is mentioned, that’s why you are getting that error. “InvariantCulture” is the correct one!

Thanks Akhil!! It worked. But getting below error… Not sure where went wrong…



I think Your Date Format is not In the Given Format for Some of the rows.


Now I am getting below error in Add data column Activity. Please advise!

Also declared “DemandAgeing” new column as String. Is this correct?

Also, The column name is taking as “Column1” though I gave “DemandAgeing” and date format is not taking as declared.


DemandAgeing is your variable na…
If it is then have u put the default value?

yes! DemandAgeing is declared as String Variable. But not given any default value.

Then it will take it as Column 1
Either you directly write the column name or set an default value

how did you solve this?

I just started working on it… will let you know in sometime

Hello @mohammed.khan39
you are getting this error because your datatable DT is not initialized…
move add data column activity after assign activity ( where you are assigning DT = ExtractDataTable…)

I got it… might help you…Main.xaml (10.8 KB)


Please find the below workflow. Can someone please someone correct and send back.
Thank you for your assistance.

First Assign activity contain DT=ExtractDataTable.Select(“DemandStatus=‘Open / Not Mapped’”).CopyToDataTable.

Add Data Column same as above. Scroll the page up to view.

your workflow look fine…
just make sure when you adding data column [DemandAgeing], its data type is of string.