This is just to log a funny bug I encountered a few days ago, on the 29th of February 2012. There was a piece of code that was comparing if a certain date is older than a year or not.
The algorithm to compare the date was creating the ‘one-year-ago date’ by substracting one unit from the current year. Something like:
<cfset aYearAgo = CreateDate(year-1,month,day)>
Obviously, this algorithm was failing on the 29th of February on the leap years (like 2012).
The solution is quite simple: instead of substracting one unit from the year, substract 365 days from the current date, using Coldfusion’s dateAdd function:
<cfset aYearAgo = DateAdd('d', -365, Now())>
Written by Dorin Moise (Published articles: 220)