CreateDate issue in ColdFusion / CFWheels

Question

I am trying to use CreateDate in CFWheels and I am getting stupid errors that I will explain in detail in sec.

To start, this is my code

<cfscript>
            lastM = dateFormat(CreateDate(year(now()),month(now())-1,day(now())),'MM');
            d = DaysInMonth(lastM);
            session.start = dateFormat(CreateDate(Year(rightnow),Month(lastM),Day(01)),'YYYY-MM-DD');
            session.end = dateFormat(CreateDate(Year(rightnow),Month(lastM),Day(d)),'YYYY-MM-DD');
            session.date = "last_month";
</cfscript>

As you can see I am trying to set my session variables start and end to the beginning and end of 'last month'. When I dump lastM and d I am getting correct values for the month and the DaysInMonth. When I use these two variables in my CreateDate method the session.start is becoming equal to 2013-01-31 and session.end is equal to 2013-01-30. I tried writing the method in many different ways but I don't see what is causing this.

I have already checked this issue Coldfusion CreateDate Issue here but it is not the same with what I am experiencing.

Answer 1

You are misusing the month() function. From the docs:

Extracts the month value from a date/time object

You are passing in a number, which CF implicitly converts to a date (probably 01/03/1900), just not the correct one. So month() is actually returning 1. That is why your results say January 2013.

A simpler way to accomplish this is to use dateAdd. Simply calculate the first of the current month. Then subtract months or days to get the start and end of the previous month. (Note: I would leave the values as date objects and only "format" them when you need to display them to the user).

<cfscript>
    today = now();
    firstOfThisMonth = CreateDate( year(today), month(today), 1);
    firstOfLastMonth = dateAdd("m", -1, firstOfThisMonth);
    endOfLastMonth = dateAdd("d", -1, firstOfThisMonth);
</cfscript>

Answer 2

Remove your day functions from the last arguments of createDate. Just use 1 and d.