ColdFusion createdate()

Question

I am just learning about ColdFusion function CreateDate. But, when I use CreateDate the value output is different. I mean it changes month to day and day to month.

<cfoutput>
<cfset txtBirthDate='07-10-1983'>
<cfset valueOf_txtBirthDate =  dateFormat(CreateDate(Year(txtBirthDate),Month(txtBirthDate),Day(txtBirthDate)),'YYYY-MMM-DD')>

#txtBirthDate#<br/><br/>
#valueOf_txtBirthDate#<br/>
</cfoutput>

The value of txtBirthDate is 07-10-1983, but the value of valueOf_txtBirthDate that CreateDate created is 1983-Jul-10. Why is it July? It is supposed to be October: 07(date), 10(month), 1983(year).

Is there something wrong with the format?

Answer 1

You are using createDate() in a very convoluted way. txtBirthDate isn't a date, so you shouldn't use it as an input for date functions like year(), month() etc. The input should already be a date object by the time you use a date function.

Let's say you start with the string 07-10-1983, where the format is mm-dd-yyyy.

txtBirthDate ='07-10-1983'; // dd-mm-yyyy

// extract the specific date parts from the string
yyyy = listLast(txtBirthDate, "-");
mm = listGetAt(txtBirthDate, 2, "-"); 
dd = listFirst(txtBirthDate, "-");

// create a date object out of those components
birthDate = createDate(yyyy, mm, dd);

// output the date object in human readable format
writeOutput(dateFormat(birthDate, "YYYY-MM-DD"));

(obviously in real code you'd not have those comments which serve only to state the obvious!)

Only ever use dateFormat() at the last point as you output it. For other date operations, use the actual date object: birthDate.

Answer 2

Because by default your date is mm/dd/yyyy format. So

<cfset txtBirthDate='07-10-1983'>

will be read as July 10th, 1983 by CF. Hence the outout...