leap years don't just complicate the calucation when a person was born on Feb 29 ... even if no one was born on feb 29, answering the question "who's birthday is in the next/last X days?" is complicated by needing to know whether the current year is a leap year...
: Or have two fields, dayofyear and dayofleapyear, then use the : right field in the right year. --wunder ...that will certianly work better then the 59.5 approach as long as X is always less then 59 ... but it's going to be a pain if X can be 90. : > If someone's birthday falls on a leap year, in most countries their : > birthday is considered to be February 28th unless it happens to be a : > leap year. You could make the field a float, encode the day number as : > 59.5, so it will match where it should, and write special handling : > along these lines: : >> if you aren't too picky about leap years, the simplest appraoch would : >> probably be to just index the day of the year they were born on as an : >> integery ... your query code will have to be a little smart about : >> moduloing arround the start/end of the year. -Hoss
