Unlock column created with a formula and modify its content

[#1]

Hello JMP team,

i have a set of data that I obtained from a temp sensor. Column 8 below has the time in the following format: hh:mm:ss:ms, the ms has three digits. I tired converting the column format to a time (only available option is h:m:s) but it is not working for some reason.

I have also used the Munger in the formula and deleted the ms portion in column 8, obtained data is in the 1st column (Time Absolute). i then tried to change the new column format to a time but it is locked and I am not able to modify it, I even tried making a copy (assuming that it is a column obtained with a formula) of the column but did not work either. 

my Goal is to get the time column with the correct format in order to plot it against other parameters.

Any recommendations/suggestions is highly appreciated.

[#2]

I created a new column called JMP Time with ms and gave it the following attributes and format

I applied the following formula to the column

In Hours( Num( Word( 1, :Column 8, ":" ) ) ) 
+ In Minutes( Num( Word( 2, :Column 8, ":" ) ) ) 
+ Num( Word( 3, :Column 8, ":" ) )
+ Num( Word( 4, :Column 8, ":" ) ) / 1000

and it gave me the following results

I believe this is what you want.

Attached is the above data table

[#3]

Thanks a lot, that is helpful.

So the formula converts the columns content into a number in seconds, and the column format (H:M:S) displays it as a time. is that right?

[#4]

Correct

[#5]

Thank you